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[51.4792N, 0.0000E] 10/06/2026, 13:00:10 Europe/London
Object: Mars [open sky map]
RA 08h 29m 58.0s Dec +20° 07' 26.5" Appar J2000
Mag: 1.09 (Estimated: JPL) Const: Cancer
Current ID: 241954
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python3 BusinessCalendarForMarsV03.py
--- Sol 7 of 668 ---
Sol Classification: Standard Business Sol
MTC Start (Airy-0): 2026-10-06 12:18:31 UTC
MTC End (Airy-0): 2026-10-07 12:58:06 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 47.4% (2026-10-06) / 52.6% (Next Day)
--- Sol 8 of 668 ---
Sol Classification: Standard Business Sol
MTC Start (Airy-0): 2026-10-07 12:58:06 UTC
MTC End (Airy-0): 2026-10-08 13:37:41 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 44.7% (2026-10-07) / 55.3% (Next Day)
--- Sol 9 of 668 ---
Sol Classification: Standard Business Sol
MTC Start (Airy-0): 2026-10-08 13:37:41 UTC
MTC End (Airy-0): 2026-10-09 14:17:17 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 42.1% (2026-10-08) / 57.9% (Next Day)
--- Sol 10 of 668 ---
Sol Classification: Standard Business Sol
MTC Start (Airy-0): 2026-10-09 14:17:17 UTC
MTC End (Airy-0): 2026-10-10 14:56:52 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 39.4% (2026-10-09) / 60.6% (Next Day)
--- Sol 11 of 668 ---
Sol Classification: Standard Business Sol
MTC Start (Airy-0): 2026-10-10 14:56:52 UTC
MTC End (Airy-0): 2026-10-11 15:36:27 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 36.7% (2026-10-10) / 63.3% (Next Day)
Mars Business Calendar Protocol | Anchored to Airy-0 (MTC) | MY 39
*** The calendar calculator we are developing shows today (Earth Tuesday October 6th) as Sol 7
The French web site we use for reference shows today as Sol 6.
Martian Year:
39
Martian Astronomical Month:
1
Solar longitude Ls:
2.7
Sol number:
6
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This post is about the names of the days of the week as expressed in English in 2026:
Here is the complete history formatted specifically for your forum, adhering strictly to FluxBB guidelines—using simple text for formulas, valid tag nesting, and list-based tables:
The Evolution of the Days of the Week: From Rome to Modern Times
The seven-day week and the names of its days reflect a blend of ancient astronomy, Roman imperial practice, and Germanic linguistics.
1. The Roman Classical System (Planetary Gods)
The ancient Romans named the days of the week after the seven visible celestial bodies known to them, associating each body with a primary deity:
Dies Solis — Sun's Day
Dies Lunae — Moon's Day
Dies Martis — Mars's Day (God of War)
Dies Mercurii — Mercury's Day (God of Commerce & Travel)
Dies Iovis — Jupiter's Day (God of Thunder & Sky)
Dies Veneris — Venus's Day (Goddess of Love)
Dies Saturni — Saturn's Day (God of Agriculture)
2. The Romance Language Path (French Direct Descent)
As Latin evolved into the Romance languages across Southern Europe, these Latin names were retained with slight phonetic shifts over time. In modern French, the direct lineage from Rome remains clearly visible:
Day | Latin Name | Modern French
Monday | Dies Lunae | Lundi
Tuesday | Dies Martis | Mardi
Wednesday | Dies Mercurii | Mercredi
Thursday | Dies Iovis | Jeudi
Friday | Dies Veneris | Vendredi
Saturday | Dies Saturni | Samedi (from Late Latin Sabbati dies)
Sunday | Dies Solis | Dimanche (from Late Latin Dies Dominica - Lord's Day)
Note on Tuesday: French Mardi directly reflects Dies Martis (Mars's Day), a root shared by Italian (Martedi) and Spanish (Martes).
3. The Germanic Shift: Substituting Norse/Germanic Deities
When Germanic tribes adapted the Roman 7-day calendar around the 3rd to 4th centuries AD, they translated the concept via interpretatio germanica—swapping the Roman gods with their closest equivalent deities in the Norse/Germanic pantheon:
Roman God | Germanic Equivalent | English Day
Mars (War) | Tiw / Tyr (War & Justice) | Tuesday (Tiw's Day)
Mercury (Messenger/Guide) | Woden / Odin (Wisdom & Magic) | Wednesday (Woden's Day)
Jupiter (Thunder) | Thor / Donar (Thunder) | Thursday (Thor's Day)
Venus (Love/Fertility) | Frigg / Freya (Love & Motherhood) | Friday (Frigg's Day)
The remaining days retained their direct heavenly designations:
Sunday: Sun's Day (Sunnandæg in Old English)
Monday: Moon's Day (Mōnandæg in Old English)
Saturday: Retained the Roman origin directly as Saturn's Day (Sæturnesdæg in Old English)
Summary Comparison
English | French | Primary Origin
Sunday | Dimanche | Sun / Lord's Day
Monday | Lundi | Moon
Tuesday | Mardi | Tiw / Mars
Wednesday | Mercredi | Woden / Mercury
Thursday | Jeudi | Thor / Jupiter
Friday | Vendredi | Frigg / Venus
Saturday | Samedi | Saturn / Sabbath
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This post is one in a series to develop a physical calendar for both Mars and Earth to use for business purposes.
A calendar that is useful for humans in both planets is turning out to be on the challenging side.
In Version 4 of the prediction program, we made a tiny change to the heading, to show that for a given Sol, it started inside an Earth day that was already in progress. We are tentatively planning to show an empty cell for an Earth Day that is entirely enclosed by a Martian Sol. That event will occur about every 37 Sols.
The first such event is predicted to occur on October 24th of 2026 on Earth.
Here is output from Version 4:
python3 BusinessCalendarForMarsV04.py
Mars Year 39 -- 5-Sol Rolling Forecast (Sols 7 to 11)
Sol 7 began at 12:18:31 UTC on October 06, 2026
Earth Date October 06 spans Sols 6 and 7--- Sol 7 of 668 ---
Sol Classification: Standard Business Sol
MTC Start (Airy-0): 2026-10-06 12:18:31 UTC
MTC End (Airy-0): 2026-10-07 12:58:06 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 47.4% (2026-10-06) / 52.6% (Next Day)
--- Sol 8 of 668 ---
Sol Classification: Standard Business Sol
MTC Start (Airy-0): 2026-10-07 12:58:06 UTC
MTC End (Airy-0): 2026-10-08 13:37:41 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 44.7% (2026-10-07) / 55.3% (Next Day)
--- Sol 9 of 668 ---
Sol Classification: Standard Business Sol
MTC Start (Airy-0): 2026-10-08 13:37:41 UTC
MTC End (Airy-0): 2026-10-09 14:17:17 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 42.1% (2026-10-08) / 57.9% (Next Day)
--- Sol 10 of 668 ---
Sol Classification: Standard Business Sol
MTC Start (Airy-0): 2026-10-09 14:17:17 UTC
MTC End (Airy-0): 2026-10-10 14:56:52 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 39.4% (2026-10-09) / 60.6% (Next Day)
--- Sol 11 of 668 ---
Sol Classification: Standard Business Sol
MTC Start (Airy-0): 2026-10-10 14:56:52 UTC
MTC End (Airy-0): 2026-10-11 15:36:27 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 36.7% (2026-10-10) / 63.3% (Next Day)
Mars Business Calendar Protocol | Anchored to Airy-0 (MTC) | MY 39
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ChatGPT and I have been struggling with how to start the New Year on Mars, while retaining connection to the Earth which is on it's own completely independent rotation. We decided to start the New Year at the instant Airy Crater crosses midnight ** after ** the planet crosses orbital longitude Zero.
Here is a write up of the discussion:
Mars Business Calendar - Defining the Beginning of a New Year
The Mars Business Calendar project has reached an important design decision concerning the beginning of a new Mars year.
The calendar is intended primarily for people living and working on Mars. Earth dates and UTC remain important - for communications, transportation, business transactions, and coordination with family, customers, and suppliers on Earth - but they should not control the fundamental passage of civil time on Mars.
Two different astronomical motions must therefore be accommodated.
Mars travels around the Sun, producing the astronomical Mars year. By established astronomical convention, a new Mars year begins when the planet reaches solar longitude Ls = 0 degrees.
At the same time, Mars rotates on its axis. The Mars Business Calendar uses Airy-0, the Martian prime meridian, as its reference for civil time. A normal Business Sol begins at mean solar midnight at Airy-0.
These two events are independent. There is no reason to expect Mars to reach Ls = 0 degrees at exactly the same instant that midnight occurs at Airy-0.
The Proposed New Year Rule
The Mars Business New Year begins at the first Airy-0 mean midnight occurring after Mars reaches Ls = 0 degrees.
This separates two related but distinct events.
The passage through Ls = 0 degrees marks the beginning of the new astronomical Mars year.
The following 00:00 Airy Mean Time marks the beginning of the new Mars Business Calendar year: Month 1, Sol 1.
The interval between those events remains part of the closing New Year's Eve of the old Business Year.
New Year's Eve therefore serves as a variable-length synchronization period. Its duration adjusts the civil calendar so that the next year can always begin cleanly at midnight on Mars.
The transition can be summarized this way:
Mars reaches Ls = 0 degrees - the new astronomical Mars year begins.
The old Business Year's New Year's Eve continues.
Airy-0 reaches its first mean midnight after Ls = 0 degrees.
NEW MARS BUSINESS YEAR - Month 1 - Sol 1 - 00:00
This arrangement provides an important property for a future Martian community: every Business Year begins at a genuine Mars civil-day boundary.
There is no fractional Sol 1, and there is no requirement that the Martian calendar wait for an Earth clock or Earth calendar date.
The Role of Earth Time
Earth time nevertheless remains valuable information and can be displayed alongside the Mars calendar.
A resident of Mars might need to schedule a communications session with Earth, arrange shipment of equipment from an Earth supplier, or order a birthday gift for a relative on Earth.
In those situations the relationship between Mars Business time and Earth UTC is important.
But those Earth dates are an overlay on the Mars calendar, rather than its foundation.
Naming the 24 Mars Months
This decision also provides a clear astronomical basis for another feature being investigated for the Mars Business Calendar: names for its 24 months.
The current proposal is to name each month for the official IAU constellation occupying the zenith above Airy-0 at the Airy midnight when that Business month begins.
For Month 1, this now gives us an unambiguous procedure:
Find the first Airy-0 mean midnight after Mars reaches Ls = 0 degrees.
Determine the celestial coordinates directly above Airy-0 at that instant.
Identify the official IAU constellation containing that point.
Use that constellation as the candidate name for Month 1.
An earlier exploratory calculation produced Taurus when the Airy midnight before the MY39 astronomical boundary was examined.
Because the Business Calendar rule has now been refined to use the first Airy midnight after Ls = 0 degrees, that calculation must be repeated before a Month 1 name is adopted.
The Developing Principle
The calendar remains a work in progress, but an important part of its framework is becoming clearer:
Mars's orbit determines when a new year becomes possible.
Mars's rotation determines when the new civil year actually begins.
Earth time tells us how that Martian calendar relates to the people and activities of Earth.
This appears to provide a stable Mars-centered foundation upon which the remainder of the Mars Business Calendar can be developed.
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In the process of move toward a physical Business Calendar for Mars, ChatGPT and i worked out a system for identifying constellations that are overhead at Airy Crater when each month transitions to the next. It turns out there are a number of duplicates, but we don't have to worry about that for a couple of months. My tentative inclination to use a star as a tie-breaker but that can wait. Here is the output from Version 2 of the new Names Generator program.
python3 Month-Name-Mars-Generator-V02.py
Mars Business Calendar - MY39
Annual Constellation Month Generator V02Month 1 Sol 1 Orion RA 05:12:30.06 Dec +15:06:02.25
Month 2 Sol 29 Gemini RA 06:08:09.85 Dec +22:19:07.81
Month 3 Sol 57 Gemini RA 07:09:48.95 Dec +27:54:33.76
Month 4 Sol 85 Cancer RA 08:17:12.76 Dec +31:17:17.16
Month 5 Sol 113 Leo RA 09:27:46.65 Dec +32:00:27.47
Month 6 Sol 141 Leo Minor RA 10:37:16.47 Dec +29:57:39.52
Month 7 Sol 168 Leo RA 11:39:50.07 Dec +25:38:25.78
Month 8 Sol 196 Coma Berenices RA 12:38:42.89 Dec +19:14:45.20
Month 9 Sol 224 Virgo RA 13:32:05.70 Dec +11:28:44.03
Month 10 Sol 252 Virgo RA 14:21:43.49 Dec +02:51:30.22
Month 11 Sol 280 Libra RA 15:09:47.60 Dec -06:10:22.05
Month 12 Sol 308 Libra RA 15:58:40.19 Dec -15:12:23.96
Month 13 Sol 335 Ophiucus RA 16:49:00.31 Dec -23:31:35.98
Month 14 Sol 363 Scorpius RA 17:47:08.89 Dec -31:14:52.78
Month 15 Sol 391 Corona Australis RA 18:53:39.09 Dec -37:24:11.31
Month 16 Sol 419 Sagittarius RA 20:08:53.62 Dec -41:13:49.94
Month 17 Sol 447 Grus RA 21:29:21.31 Dec -42:05:04.43
Month 18 Sol 475 Grus RA 22:48:08.13 Dec -39:47:41.97
Month 19 Sol 502 Sculptor RA 23:57:07.12 Dec -35:00:35.87
Month 20 Sol 530 Sculptor RA 00:59:50.06 Dec -28:05:45.03
Month 21 Sol 558 Cetus RA 01:55:03.40 Dec -19:54:51.38
Month 22 Sol 586 Eridanus RA 02:45:26.21 Dec -11:02:50.34
Month 23 Sol 614 Eridanus RA 03:33:38.27 Dec -01:57:46.93
Month 24 Sol 642 Taurus RA 04:22:08.59 Dec +06:55:45.95Annual month table written to:
/home/tahanson/PythonCalendar/MY39_Months.csv
MY39 MONTH 1 VERIFICATION
-------------------------
Constellation: Orion
Zenith RA: 05:12:30.06
Zenith Dec: +15:06:02.25PASS: Month 1 independently identified as Orion.
DUPLICATE CONSTELLATION REPORT
------------------------------
Gemini Months 2, 3
Leo Months 5, 7
Virgo Months 9, 10
Libra Months 11, 12
Grus Months 17, 18
Sculptor Months 19, 20
Eridanus Months 22, 23NOTE: Duplicate names are valid astronomical results in V02.
No automatic renaming has been applied.MY39 annual constellation table passed the Month 1 acceptance test.
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this post contains the result of a 100 Mars Year projection that shows that the structure under consideration for the Mars Business Calendar has a remarkable property.... Approximately every other Mars Year the residents will enjoy a Leap Soll. This comes about because of the interaction of the orbit of Mars and the rotation rate of Mars. I was, and still am, surprised by this outcome of the investigation. Going in, I assumed we would extend New Year's Eve by some number of hours. Apparently celestial mechanics provides this elegant solution. And for those who might be curious, there are the NASA data sets we used:
ls kernels
de440.bsp naif0012.tls pck00011.tpcAnd here are the results:
python3 Mars-Year-Cycle-Test-V03.py
Ls axis calibration offset: 0.0 degreesMARS BUSINESS CALENDAR
100-YEAR CYCLE TEST V03MY Ls=0 UTC MTC Wait(h) Business New Year UTC Sols
----------------------------------------------------------------------------------------------------
39 2026-09-30 08:11:06.675 UTC 2.114 22.488 2026-10-01 06:40:22.543 UTC REFERENCE
40 2028-08-17 07:06:50.611 UTC 15.923 8.299 2028-08-17 15:24:45.568 UTC 668.000000
41 2030-07-05 06:59:52.114 UTC 6.662 17.814 2030-07-06 00:48:43.405 UTC 668.999996
42 2032-05-22 06:32:18.359 UTC 21.067 3.013 2032-05-22 09:33:06.739 UTC 668.000004
43 2034-04-09 05:25:17.363 UTC 10.832 13.530 2034-04-09 18:57:05.077 UTC 669.000001
44 2036-02-25 05:08:33.146 UTC 1.413 23.208 2036-02-26 04:21:03.194 UTC 668.999999
45 2038-01-12 04:33:05.004 UTC 15.689 8.539 2038-01-12 13:05:26.144 UTC 668.000000
46 2039-11-30 03:12:36.514 UTC 5.236 19.280 2039-11-30 22:29:24.989 UTC 669.000007
47 2041-10-17 02:48:39.915 UTC 19.699 4.419 2041-10-17 07:13:48.480 UTC 668.000006
48 2043-09-04 02:33:45.719 UTC 10.309 14.067 2043-09-04 16:37:46.618 UTC 668.999999
49 2045-07-22 01:38:03.623 UTC 0.258 24.395 2045-07-23 02:01:44.856 UTC 669.000000
50 2047-06-09 00:53:29.377 UTC 14.387 9.877 2047-06-09 10:46:07.699 UTC 667.999998
51 2049-04-26 00:13:25.096 UTC 4.589 19.945 2049-04-26 20:10:05.751 UTC 668.999998
52 2051-03-13 22:48:04.365 UTC 18.057 6.107 2051-03-14 04:54:29.110 UTC 668.000004
53 2053-01-28 22:30:05.873 UTC 8.617 15.806 2053-01-29 14:18:27.953 UTC 669.000007
54 2054-12-16 22:23:51.454 UTC 23.368 0.650 2054-12-16 23:02:50.626 UTC 667.999996
55 2056-11-02 21:30:29.918 UTC 13.354 10.939 2056-11-03 08:26:49.425 UTC 669.000006
56 2058-09-20 20:29:58.214 UTC 3.224 21.347 2058-09-21 17:50:47.055 UTC 668.999993
57 2060-08-07 20:03:48.359 UTC 17.652 6.523 2060-08-08 02:35:10.290 UTC 668.000003
58 2062-06-25 18:49:18.769 UTC 7.295 17.164 2062-06-26 11:59:09.032 UTC 669.000006
59 2064-05-12 17:47:42.455 UTC 21.148 2.930 2064-05-12 20:43:31.808 UTC 667.999998
60 2066-03-30 17:35:09.251 UTC 11.796 12.539 2066-03-31 06:07:29.938 UTC 668.999999
61 2068-02-15 17:26:34.229 UTC 2.509 22.082 2068-02-16 15:31:28.250 UTC 669.000001
62 2070-01-02 16:37:45.460 UTC 16.569 7.635 2070-01-03 00:15:51.573 UTC 668.000004
63 2071-11-20 16:06:36.872 UTC 6.916 17.554 2071-11-21 09:39:50.320 UTC 669.000006
64 2073-10-07 15:06:40.031 UTC 20.796 3.292 2073-10-07 18:24:12.570 UTC 667.999992
65 2075-08-25 13:50:33.268 UTC 10.413 13.961 2075-08-26 03:48:11.140 UTC 669.000004
66 2077-07-12 13:35:29.419 UTC 1.021 23.611 2077-07-13 13:12:09.625 UTC 669.000003
67 2079-05-30 13:17:13.490 UTC 15.576 8.655 2079-05-30 21:56:32.785 UTC 668.000002
68 2081-04-16 12:11:20.860 UTC 5.359 19.153 2081-04-17 07:20:31.488 UTC 669.000005
69 2083-03-04 11:37:25.269 UTC 19.661 4.458 2083-03-04 16:04:53.988 UTC 667.999994
70 2085-01-19 11:16:33.806 UTC 10.175 14.205 2085-01-20 01:28:52.860 UTC 669.000007
71 2086-12-07 09:50:09.726 UTC 23.625 0.385 2086-12-07 10:13:15.871 UTC 668.000000
72 2088-10-24 09:09:22.766 UTC 13.816 10.464 2088-10-24 19:37:14.247 UTC 669.000002
73 2090-09-11 08:56:52.332 UTC 4.465 20.072 2090-09-12 05:01:12.146 UTC 668.999996
74 2092-07-29 08:06:24.667 UTC 18.498 5.653 2092-07-29 13:45:35.571 UTC 668.000005
75 2094-06-16 07:11:52.368 UTC 8.466 15.961 2094-06-16 23:09:33.606 UTC 668.999998
76 2096-05-03 06:40:33.849 UTC 22.810 1.223 2096-05-03 07:53:57.175 UTC 668.000007
77 2098-03-21 05:20:10.460 UTC 12.358 11.962 2098-03-21 17:17:55.120 UTC 668.999997
78 2100-02-06 04:52:28.376 UTC 2.760 21.824 2100-02-07 02:41:53.371 UTC 669.000000
79 2101-12-25 04:55:24.894 UTC 17.660 6.514 2101-12-25 11:26:16.981 UTC 668.000007
80 2103-11-12 04:17:33.667 UTC 7.898 16.545 2103-11-12 20:50:15.089 UTC 668.999999
81 2105-09-29 03:13:41.146 UTC 21.714 2.349 2105-09-29 05:34:37.658 UTC 667.999995
82 2107-08-17 02:46:44.951 UTC 12.129 12.198 2107-08-17 14:58:36.797 UTC 669.000010
83 2109-07-04 01:46:32.990 UTC 2.004 22.601 2109-07-05 00:22:35.169 UTC 669.000002
84 2111-05-22 00:32:20.485 UTC 15.652 8.577 2111-05-22 09:06:57.753 UTC 667.999995
85 2113-04-08 00:13:21.287 UTC 6.196 18.293 2113-04-08 18:30:55.889 UTC 668.999999
86 2115-02-24 00:08:42.039 UTC 20.973 3.110 2115-02-24 03:15:18.732 UTC 667.999998
87 2117-01-10 23:21:23.903 UTC 11.057 13.298 2117-01-11 12:39:17.930 UTC 669.000011
88 2118-11-28 22:39:18.299 UTC 1.227 23.399 2118-11-29 22:03:15.662 UTC 668.999994
89 2120-10-15 21:48:58.271 UTC 15.262 8.978 2120-10-16 06:47:38.725 UTC 668.000001
90 2122-09-02 20:20:24.637 UTC 4.678 19.854 2122-09-03 16:11:37.425 UTC 669.000005
91 2124-07-20 19:50:15.011 UTC 19.041 5.096 2124-07-21 00:55:59.888 UTC 667.999994
92 2126-06-07 19:38:51.479 UTC 9.708 14.685 2126-06-08 10:19:58.689 UTC 669.000006
93 2128-04-24 18:42:11.863 UTC 23.640 0.370 2128-04-24 19:04:22.163 UTC 668.000005
94 2130-03-12 17:55:59.004 UTC 13.743 10.539 2130-03-13 04:28:19.638 UTC 668.999991
95 2132-01-28 17:51:53.305 UTC 4.528 20.007 2132-01-29 13:52:18.274 UTC 669.000004
96 2133-12-15 16:35:00.519 UTC 18.133 6.028 2133-12-15 22:36:41.579 UTC 668.000004
97 2135-11-02 15:42:25.367 UTC 8.132 16.304 2135-11-03 08:00:39.762 UTC 668.999999
98 2137-09-19 15:33:50.096 UTC 22.845 1.187 2137-09-19 16:45:02.582 UTC 667.999998
99 2139-08-07 14:56:18.154 UTC 13.088 11.212 2139-08-08 02:09:00.973 UTC 669.000002
100 2141-06-24 13:57:44.878 UTC 2.990 21.588 2141-06-25 11:33:00.031 UTC 669.000009
101 2143-05-12 13:29:36.180 UTC 17.386 6.796 2143-05-12 20:17:22.421 UTC 667.999993
102 2145-03-29 12:18:39.471 UTC 7.087 17.378 2145-03-30 05:41:21.046 UTC 669.000004
103 2147-02-14 11:32:50.196 UTC 21.196 2.882 2147-02-14 14:25:43.862 UTC 667.999998
104 2149-01-01 11:31:38.806 UTC 12.028 12.301 2149-01-01 23:49:42.808 UTC 669.000008
105 2150-11-19 11:01:22.752 UTC 2.389 22.205 2150-11-20 09:13:41.088 UTC 669.000000
106 2152-10-06 09:51:03.900 UTC 16.100 8.117 2152-10-06 17:58:04.327 UTC 668.000003
107 2154-08-24 09:12:42.196 UTC 6.330 18.155 2154-08-25 03:22:01.957 UTC 668.999993
108 2156-07-11 08:24:59.107 UTC 20.408 3.691 2156-07-11 12:06:24.958 UTC 668.000000
109 2158-05-29 07:02:09.015 UTC 9.917 14.471 2158-05-29 21:30:23.199 UTC 669.000000
110 2160-04-15 06:34:21.518 UTC 0.318 24.333 2160-04-16 06:54:22.035 UTC 669.000007
111 2162-03-03 06:34:19.422 UTC 15.169 9.074 2162-03-03 15:38:45.029 UTC 668.000000
112 2164-01-19 05:58:39.550 UTC 5.442 19.068 2164-01-20 01:02:43.492 UTC 669.000003
113 2165-12-06 05:11:23.887 UTC 19.528 4.595 2165-12-06 09:47:06.921 UTC 668.000005
114 2167-10-24 04:34:53.387 UTC 9.788 14.603 2167-10-24 19:11:04.756 UTC 668.999995
115 2169-09-10 03:09:18.506 UTC 23.251 0.769 2169-09-10 03:55:27.965 UTC 668.000002
116 2171-07-29 02:27:53.791 UTC 13.431 10.859 2171-07-29 13:19:26.583 UTC 669.000004
117 2173-06-15 02:23:10.936 UTC 4.207 20.337 2173-06-15 22:43:25.062 UTC 669.000003
118 2175-05-03 01:38:04.925 UTC 18.327 5.829 2175-05-03 07:27:48.140 UTC 668.000001
119 2177-03-20 00:39:07.599 UTC 8.223 16.211 2177-03-20 16:51:46.148 UTC 668.999997
120 2179-02-05 00:37:28.479 UTC 23.048 0.978 2179-02-05 01:36:09.119 UTC 668.000000
121 2180-12-22 23:30:23.358 UTC 12.812 11.496 2180-12-23 11:00:07.333 UTC 669.000000
122 2182-11-09 22:18:43.823 UTC 2.501 22.090 2182-11-10 20:24:06.133 UTC 669.000006
123 2184-09-26 22:02:59.994 UTC 17.098 7.092 2184-09-27 05:08:29.395 UTC 668.000003
124 2186-08-14 21:33:41.785 UTC 7.475 16.979 2186-08-15 14:32:27.520 UTC 668.999999
125 2188-07-01 20:31:47.493 UTC 21.323 2.751 2188-07-01 23:16:50.316 UTC 667.999998
126 2190-05-19 19:59:02.587 UTC 11.644 12.696 2190-05-20 08:40:48.744 UTC 669.000002
127 2192-04-05 19:02:15.605 UTC 1.574 23.042 2192-04-06 18:04:47.095 UTC 669.000001
128 2194-02-21 18:01:37.674 UTC 15.443 8.792 2194-02-22 02:49:10.255 UTC 668.000002
129 2196-01-09 17:56:20.594 UTC 6.209 18.280 2196-01-10 12:13:08.510 UTC 669.000000
130 2197-11-26 17:39:12.634 UTC 20.783 3.305 2197-11-26 20:57:31.642 UTC 668.000002
131 2199-10-14 16:36:14.259 UTC 10.614 13.754 2199-10-15 06:21:29.602 UTC 668.999997
132 2201-09-01 15:51:41.308 UTC 0.743 23.896 2201-09-02 15:45:27.984 UTC 669.000002
133 2203-07-20 15:19:49.374 UTC 15.078 9.167 2203-07-21 00:29:51.140 UTC 668.000002
134 2205-06-06 13:57:09.489 UTC 4.589 19.944 2205-06-07 09:53:49.588 UTC 669.000002
135 2207-04-24 13:16:35.836 UTC 18.783 5.360 2207-04-24 18:38:13.024 UTC 668.000005
136 2209-03-11 13:14:45.550 UTC 9.605 14.790 2209-03-12 04:02:11.072 UTC 668.999998
137 2211-01-27 12:49:31.973 UTC 0.048 24.611 2211-01-28 13:26:09.831 UTC 669.000006
138 2212-12-14 11:53:21.616 UTC 13.989 10.286 2212-12-14 22:10:32.565 UTC 667.999997MY39 ACCEPTANCE TEST
--------------------
Reference: 2026-10-01 06:38:57+00:00
Calculated: 2026-10-01 06:40:22.543000+00:00
Difference: 85.543 secondsPASS: MY39 agrees with the established Business New Year reference.
100-YEAR SUMMARY
----------------
Minimum wait after Ls=0: 0.370 hours
Maximum wait after Ls=0: 24.611 hoursShortest civil year: 667.999992 sols
Longest civil year: 669.000011 sols
Average civil year: 668.585860 solsYears nearest 668 sols: 41
Years nearest 669 sols: 58
Other: 0Results written to:
/home/tahanson/PythonCalendar/Mars-Year-Cycle-100-V03.csv
Apparently the Business Calendar for Mars will need no other adjustments over 100 Mars years (200 or so Earth years)
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===
Today on Mars: 0039/01/06 Friday Days of the week OFFSET 4 with Earth. (count from Mars to Earth )
Sol 006 Business Month 01 First month of Quarter 1 of Year 39
Today on Earth: 2026/10/06 Tuesday
>16
To see how this calendar works, we show the standard 28 day month at the bottom of this daily report.
There are 20 months of 28 Sols and 4 months of 27 Sols at the end of the four six-month quarters.
New Years Eve is extended to align the Business Calendar for Mars with the Astronomical calendar.
Business and Astronomical both start at zero (to the nanosecond) on New Year's Day.
This calendar has been in operation for two full Mars years (36 and 37). We are in Year 38
This calendar is NOT the Darian Calendar!
Per http://www-mars.lmd.jussieu.fr/mars/tim … _time.html also see: in-the-sky.org for opposition/perigee/aphelion
Martian Year: 39 Martian Astronomical Interval in 12 interval format: 1 <<== The Astronomical interval
Check Longitude: the interval will increment when longitude reaches 30 degrees
===
Solar Longitude: 002.7 Sol Number: 006 Change in degrees is +.5 Julian date is: J0039006
Solar Longitude: 002.2 Sol Number: 005 Change in degrees is +.5 Julian date is: J0039005
Solar Longitude: 001.7 Sol Number: 004 Change in degrees is +.5 Julian date is: J0039004
#6>
Note that Solar Longitude measurement varies as a function of location in orbit. Ls 0 is the moment when the Sun appears to transit from one hemisphere to the other. Update from Mars.NASA.gov (The Sun crosses the equator of Mars (Vernal Equinox)). The transition itself is a function of the tilt of an object with respect to the Solar plane. Per squarewidget.com, Hipparchus created the celestial coordinate system we use today.
Note#2: https://theskylive.com/mars-tracker This web site shows the astronomical position of Mars as seen from Earth
Todo: At next Aphelion/Perihelion record the Mars date as J00##### (and set Search term)
Perihelion occurred in 2026 at Ls 251 on Sol 486 - Earth Date 2026/03/27 Next: (estimated) 2028/05/15
Perihelion occurred in 2024 at Ls 251 on Sol 485 - Earth Date 2024/05/08 Next: (estimated) 2026/03/06 (actual) 2026/03/26
Perihelion occurred in 2022 at Ls 251 on Sol 485 - Earth Date 2022/06/21 Next: (actual) 2024/05/08
Aphelion Earth Dates: Next: 2027/03/04 Earlier: 2025/04/16, 2023/05/30, 2021/07/12, 2019/08/25, 2017/10/07, 2015/11/20
Aphelion occurred at--- Ls 071 on Sol 152.
Aphelion occurred near Ls 070 on Sol 153 (per http://www.planetary.org)
Note#3: The computations below are dependent upon both the computations provided by the reference web site and by accuracy of recording of the time of observations. The calculations use tenths of hours. The Sun Distance needs to be captured at the moment the time increments to a given tenth.
Note on data below: The figure quoted after distance is a rate of progress along the orbital path [exact meaning to be determined]
Minus prefix means Mars is approaching the Sun. Plus prefix means Mars is moving away from the Sun.
The figure computed to the right of "Difference" is the rate of change of the distance to Sun. Increasing to Aphelion/Decreasing to Perihelion.
Aphelion of Mars is due March 04, 2027 Sol 151-152 Note velocity of Mars was 22.0 km/s nearing Aphelion (21.97 km/s)
Perhelion of Mars is due May, 2028 Sol 251 Note velocity of Mars was 26.5 km/s nearing Perihelion 2026/03/26
Mars passed through 0 Radial Distance on outbound leg Sol 633 of Year 38 2026/08/25 Solar Longitude is 341.1 (90 degrees season)
Mars will pass through 0 Radial Distance on inbound leg Sol 219 at longitude 71 270 degrees seasonal)
Conversion between seasons and physical frameworks: L_s = theta + 251 theta = L_s - 251
===
Distance: Mars >> Sun per theskylive.com: 234,118,730 km [23.5 km/s] Difference is +181788 <= +7575 km/hour at 12.0 on 10/06 (time 12:00) (24.0 hours)
Distance: Mars >> Sun per theskylive.com: 233,936,942 km [23.5 km/s] Difference is +182386 <= +7599 km/hour at 12.0 on 10/05 (time 12:00) (24.0 hours)
Distance: Mars >> Sun per theskylive.com: 233,754,556 km [23.5 km/s] Difference is +182974 <= +7624 km/hour at 12.0 on 10/04 (time 12:00) (24.0 hours)
>13
Velocity along the orbit is NOT the same thing as velocity change of the radial distance to the Sun. Both are shown in the section above.
Observation: The sky view is ** filled ** with objects and some have been recorded and given identification by humans or their robot assistants
And! ** All ** the location assignments are from the perspective of Earth. The entire catalog needs to be adjusted when inter-stellar travel begins
The work that lies ahead for the astronomical community is daunting - there is work ahead for centuries
2022/01/19 - All current (existing) stellar catalogs are computed with reference to the Earth. Another civilization would use it's planet as reference.
Perhaps a Milky Way frame of reference will become necessary at some point. The Earth is as good a Zero point as any, for humans.
=== Mars is in Regular movement as seen from Earth.
Mars is in cancer – we in NewMars have an opportunity to visit some of the stars in Cancer during this period
Next ahead: Galaxy just below path ahead of 5.5 hours marker: 1615686 RA 8h 30m 56.1s
Star in path 1387-40-1 RA 8h 28m 44.7s Day 2 above 5.5 hours marker
We are in a field of galaxies! PGC 1622204 RA 8h 26m 21.6s Day 2 just past Mars Day 3 still visible before reset
14>
Zoom Out Capability As a general observation ... I've become increasingly interested in knowing what the larger view of the sky might be like.
The site: theskylive.com does a terrific job of matching the view from Earth towards Mars, against a background of actual astronomical plates.
I wish there were a way (or rather, I wish I ** knew ** about a way that may exist) to enlarge the view until the entire galaxy is in view (Zoom out)
Update 2022/12/08 TheSkyLive.com provides a large view of selected objects: Select [Major Bodies] Then select [Information] in the body of interest
Update 2022/12/08 Scroll down to (body) Position and Finder Charts. Field of view is 50x30 degrees.
Light travel in one second is (about) 300,000 kilometers. The distance covered in one minute is about 18,000,000 kilometers. Estimated light times:
1:18,2:36,3:54,4:72,5:90,6:108,7:126,8:144,9:162,10:180,11:198,12:216,13:234,14:252,15:270,16:288,17:306,18:324, 19:342,20:360,21:378,22:396
Light travel time today is between 14 and 15 minutes. Communications delay would be 28+ minutes round trip.
=== Time estimate will change below 252 megaKm
Earth Distance in km: 2026/10/06 243,408,282 (decreasing)
Earth Distance in km: 2026/10/05 244,467,245 (decreasing)
Earth Distance in km: 2026/10/04 245,519,175 (decreasing)
>15
Maximum Earth-Mars distance is estimated to be 401 million kilometers (both at apogee and opposite vs Sun) Minimum is about 56 million kilometers
Mars and Earth were in Opposition (Earth center) in December of 2022. The date coincided with a (very rare) occultation of Mars by the Moon.
Mars and Earth were in Conjunction (Sun center) in November of 2023.
Mars and Earth appear to have been as close as they will get in Year 36. 81,454,323 kilometers on J0036644 Time: 4.53 minutes - 9 minutes round trip
In his online interview with Dr. Zubrin at the 2020 Mars Conference, Elon Musk reminded the audience that communications with Mars will necessarily include an intermediary station to handle traffic when the Sun is between Mars and Earth. Communications delays in that circumstance will increase due to the extra distance to be covered. Mr. Musk indicated he expects such communication will be handled by laser. Location would be optimum at poles of solar plane.
This web site offers an online model of the solar system: www.solarsystemscope.com
This web site offers an online orrery view of the Solar System: https://www.theplanetstoday.com/
===
Sol 006 is in Month 01 of a Proposed 24 month calendar. See Post 19 of Holidays topic for a summary. <<< 37 is skip day on Mars
Month 01 extends from Sol 1 through 28. <<== There are 28 days in Month 01. See post 82 of Holidays topic for current details
Direct path to source: http://newmars.com/forums/viewtopic.php … 57#p154257
Sol 006 is Friday in the Proposed Business calendar for Mars. Sol 667 Skip Day on Mars. Next is near 37 of Year 39
##
The Next New Year's on Mars will occur when Solar Longitude reaches 360 degrees. Year 38 started November 12, 2024 on Earth
Per www.planetary.org Year 36 started 2021/02/07 on Earth. Mars Year 37 began 2022/12/27 on Earth.
Days of the Week Alignment:
Days of the week fall behind Earth due to the longer Sol, but they also change when Friday is omitted at the end of a Quarter
337 Earth days were observed to elapse in the 2020 weekday cycle. There were 7 week day transitions and 2 Quarter ends.
The next cycle began on the first Sol of the period of coincidence. The alignment of weekdays interval is in the range: (310 - 337)
To find the first day of a period of coincidence: Set up: SearchTerm(colon) and (colon)Alignment and J0036* or J0037*
The most recent End-Of-Quarter change occurred: … The search specified above gave 11 pages of results.
For current weather on Mars see:
***https://mars.nasa.gov/insight/weather/***
***Insight's weather info has been suspended and now is directing to msl*** <<-- Insight's mission is over (2022)
https://mars.nasa.gov/msl/weather/
Per SpaceNut: Here is another web page by NASA containing the latest news releases
https://mars.nasa.gov/news/?page=0&per_ … ope=Latest
All forum members are invited to post significant events for this day.
Events of interest will be ON Mars, or relate to Mars. Examples are launches, landings, discoveries
Standard Month in Mars Business Calendar Copyright ® 2023 NewMars.com Mars Society
Su Mo Tu We Th Fr Sa
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
Recruiting text may be found at the bottom of this post: http://newmars.com/forums/viewtopic.php … 57#p154257
Copyright the Mars Society All Rights Reserved
Month 1 of 24: First month of Quarter 1 and first month of Mars Year 39
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Place Holder for today's Calendar update
[51.4792N, 0.0000E] 10/07/2026, 13:00:02 Europe/London
Object: Mars [open sky map]
RA 08h 32m 20.4s Dec +20° 00' 08.6" Appar J2000
Mag: 1.09 (Estimated: JPL) Const: Cancer
Current ID: 241978
Total number of registered users: 19,630
Total number of topics: 9,139
Total number of posts: 237,658
Newest registered user: Redfoot-2026
Registered users online: 2
Guests online: 327
Online: Oldfart1939, tahanson43206
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The report below was generated by Version 5 of the new Python program to generate predictions for a future physical calendar.
We will continue to report the data from our French reference site while we work on the Business Calendar For Mars programs.
python BusinessCalendarForMarsV05.py
Mars Year 39 -- Month 1: Orion -- 5-Sol Rolling Forecast (Sols 8 to 12)
Sol 8 began at 12:58:06 UTC on October 07, 2026
Earth Date October 07 spans Sols 7 and 8--- Sol 8 of 668 ---
Sol Classification: Standard Business Sol
MTC Start (Airy-0): 2026-10-07 12:58:06 UTC
MTC End (Airy-0): 2026-10-08 13:37:41 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 44.7% (2026-10-07) / 55.3% (Next Day)
--- Sol 9 of 668 ---
Sol Classification: Standard Business Sol
MTC Start (Airy-0): 2026-10-08 13:37:41 UTC
MTC End (Airy-0): 2026-10-09 14:17:17 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 42.1% (2026-10-08) / 57.9% (Next Day)
--- Sol 10 of 668 ---
Sol Classification: Standard Business Sol
MTC Start (Airy-0): 2026-10-09 14:17:17 UTC
MTC End (Airy-0): 2026-10-10 14:56:52 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 39.4% (2026-10-09) / 60.6% (Next Day)
--- Sol 11 of 668 ---
Sol Classification: Standard Business Sol
MTC Start (Airy-0): 2026-10-10 14:56:52 UTC
MTC End (Airy-0): 2026-10-11 15:36:27 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 36.7% (2026-10-10) / 63.3% (Next Day)
--- Sol 12 of 668 ---
Sol Classification: Standard Business Sol
MTC Start (Airy-0): 2026-10-11 15:36:27 UTC
MTC End (Airy-0): 2026-10-12 16:16:02 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 34.0% (2026-10-11) / 66.0% (Next Day)
Mars Business Calendar Protocol | Anchored to Airy-0 (MTC) | MY 39
In this version, we have looked up the constellation that is overhead at Airy Crater ... I'm not sure of the date for which calculations are performed. I asked for midnight of the Sol between the previous month and the current one, but the calculation may be done for ** this ** Sol. I'll ask ChatGPT to clarify that point.
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===
Today on Mars: 0039/01/07 Saturday Days of the week OFFSET 4 with Earth. (count from Mars to Earth )
Sol 007 Business Month 01 First month of Quarter 1 of Year 39
Today on Earth: 2026/10/07 Wednesday
>16
To see how this calendar works, we show the standard 28 day month at the bottom of this daily report.
There are 20 months of 28 Sols and 4 months of 27 Sols at the end of the four six-month quarters.
New Years Eve is extended to align the Business Calendar for Mars with the Astronomical calendar.
Business and Astronomical both start at zero (to the nanosecond) on New Year's Day.
This calendar has been in operation for two full Mars years (36 and 37). We are in Year 38
This calendar is NOT the Darian Calendar!
Per http://www-mars.lmd.jussieu.fr/mars/tim … _time.html also see: in-the-sky.org for opposition/perigee/aphelion
Martian Year: 39 Martian Astronomical Interval in 12 interval format: 1 <<== The Astronomical interval
Check Longitude: the interval will increment when longitude reaches 30 degrees
===
Solar Longitude: 003.2 Sol Number: 007 Change in degrees is +.5 Julian date is: J0039007
Solar Longitude: 002.7 Sol Number: 006 Change in degrees is +.5 Julian date is: J0039006
Solar Longitude: 002.2 Sol Number: 005 Change in degrees is +.5 Julian date is: J0039005
#6>
Note that Solar Longitude measurement varies as a function of location in orbit. Ls 0 is the moment when the Sun appears to transit from one hemisphere to the other. Update from Mars.NASA.gov (The Sun crosses the equator of Mars (Vernal Equinox)). The transition itself is a function of the tilt of an object with respect to the Solar plane. Per squarewidget.com, Hipparchus created the celestial coordinate system we use today.
Note#2: https://theskylive.com/mars-tracker This web site shows the astronomical position of Mars as seen from Earth
Todo: At next Aphelion/Perihelion record the Mars date as J00##### (and set Search term)
Perihelion occurred in 2026 at Ls 251 on Sol 486 - Earth Date 2026/03/27 Next: (estimated) 2028/05/15
Perihelion occurred in 2024 at Ls 251 on Sol 485 - Earth Date 2024/05/08 Next: (estimated) 2026/03/06 (actual) 2026/03/26
Perihelion occurred in 2022 at Ls 251 on Sol 485 - Earth Date 2022/06/21 Next: (actual) 2024/05/08
Aphelion Earth Dates: Next: 2027/03/04 Earlier: 2025/04/16, 2023/05/30, 2021/07/12, 2019/08/25, 2017/10/07, 2015/11/20
Aphelion occurred at--- Ls 071 on Sol 152.
Aphelion occurred near Ls 070 on Sol 153 (per http://www.planetary.org)
Note#3: The computations below are dependent upon both the computations provided by the reference web site and by accuracy of recording of the time of observations. The calculations use tenths of hours. The Sun Distance needs to be captured at the moment the time increments to a given tenth.
Note on data below: The figure quoted after distance is a rate of progress along the orbital path [exact meaning to be determined]
Minus prefix means Mars is approaching the Sun. Plus prefix means Mars is moving away from the Sun.
The figure computed to the right of "Difference" is the rate of change of the distance to Sun. Increasing to Aphelion/Decreasing to Perihelion.
Aphelion of Mars is due March 04, 2027 Sol 151-152 Note velocity of Mars was 22.0 km/s nearing Aphelion (21.97 km/s)
Perhelion of Mars is due May, 2028 Sol 251 Note velocity of Mars was 26.5 km/s nearing Perihelion 2026/03/26
Mars passed through 0 Radial Distance on outbound leg Sol 633 of Year 38 2026/08/25 Solar Longitude is 341.1 (90 degrees season)
Mars will pass through 0 Radial Distance on inbound leg Sol 219 at longitude 71 270 degrees seasonal)
Conversion between seasons and physical frameworks: L_s = theta + 251 theta = L_s - 251
===
Distance: Mars >> Sun per theskylive.com: 234,299,850 km [23.5 km/s] Difference is +181120 <= +7547 km/hour at 12.0 on 10/07 (time 12:00) (24.0 hours)
Distance: Mars >> Sun per theskylive.com: 234,118,730 km [23.5 km/s] Difference is +181788 <= +7575 km/hour at 12.0 on 10/06 (time 12:00) (24.0 hours)
Distance: Mars >> Sun per theskylive.com: 233,936,942 km [23.5 km/s] Difference is +182386 <= +7599 km/hour at 12.0 on 10/05 (time 12:00) (24.0 hours)
>13
Velocity along the orbit is NOT the same thing as velocity change of the radial distance to the Sun. Both are shown in the section above.
Observation: The sky view is ** filled ** with objects and some have been recorded and given identification by humans or their robot assistants
And! ** All ** the location assignments are from the perspective of Earth. The entire catalog needs to be adjusted when inter-stellar travel begins
The work that lies ahead for the astronomical community is daunting - there is work ahead for centuries
2022/01/19 - All current (existing) stellar catalogs are computed with reference to the Earth. Another civilization would use it's planet as reference.
Perhaps a Milky Way frame of reference will become necessary at some point. The Earth is as good a Zero point as any, for humans.
=== Mars is in Regular movement as seen from Earth.
Mars is in cancer – we in NewMars have an opportunity to visit some of the stars in Cancer during this period
Next ahead:
Galaxy just below path ahead of 5.5 hours marker: 1615686 RA 8h 30m 56.1s Day 2 just past Mars
Star in path 1387-40-1 RA 8h 28m 44.7s Day 2 above 5.5 hours marker Day 3 still there but only for a few minutes
14>
Zoom Out Capability As a general observation ... I've become increasingly interested in knowing what the larger view of the sky might be like.
The site: theskylive.com does a terrific job of matching the view from Earth towards Mars, against a background of actual astronomical plates.
I wish there were a way (or rather, I wish I ** knew ** about a way that may exist) to enlarge the view until the entire galaxy is in view (Zoom out)
Update 2022/12/08 TheSkyLive.com provides a large view of selected objects: Select [Major Bodies] Then select [Information] in the body of interest
Update 2022/12/08 Scroll down to (body) Position and Finder Charts. Field of view is 50x30 degrees.
Light travel in one second is (about) 300,000 kilometers. The distance covered in one minute is about 18,000,000 kilometers. Estimated light times:
1:18,2:36,3:54,4:72,5:90,6:108,7:126,8:144,9:162,10:180,11:198,12:216,13:234,14:252,15:270,16:288,17:306,18:324, 19:342,20:360,21:378,22:396
Light travel time today is between 14 and 15 minutes. Communications delay would be 28+ minutes round trip.
=== Time estimate will change below 252 megaKm
Earth Distance in km: 2026/10/07 242,342,656 (decreasing)
Earth Distance in km: 2026/10/06 243,408,282 (decreasing)
Earth Distance in km: 2026/10/05 244,467,245 (decreasing)
>15
Maximum Earth-Mars distance is estimated to be 401 million kilometers (both at apogee and opposite vs Sun) Minimum is about 56 million kilometers
Mars and Earth were in Opposition (Earth center) in December of 2022. The date coincided with a (very rare) occultation of Mars by the Moon.
Mars and Earth were in Conjunction (Sun center) in November of 2023.
Mars and Earth appear to have been as close as they will get in Year 36. 81,454,323 kilometers on J0036644 Time: 4.53 minutes - 9 minutes round trip
In his online interview with Dr. Zubrin at the 2020 Mars Conference, Elon Musk reminded the audience that communications with Mars will necessarily include an intermediary station to handle traffic when the Sun is between Mars and Earth. Communications delays in that circumstance will increase due to the extra distance to be covered. Mr. Musk indicated he expects such communication will be handled by laser. Location would be optimum at poles of solar plane.
This web site offers an online model of the solar system: www.solarsystemscope.com
This web site offers an online orrery view of the Solar System: https://www.theplanetstoday.com/
===
Sol 007 is in Month 01 of a Proposed 24 month calendar. See Post 19 of Holidays topic for a summary. <<< 37 is skip day on Mars
Month 01 extends from Sol 1 through 28. <<== There are 28 days in Month 01. See post 82 of Holidays topic for current details
Direct path to source: http://newmars.com/forums/viewtopic.php … 57#p154257
Sol 007 is Saturday in the Proposed Business calendar for Mars. Sol 667 Skip Day on Mars. Next is near 24 or 37 of Year 39
##
The Next New Year's on Mars will occur when Solar Longitude reaches 360 degrees. Year 38 started November 12, 2024 on Earth
Per www.planetary.org Year 36 started 2021/02/07 on Earth. Mars Year 37 began 2022/12/27 on Earth.
Days of the Week Alignment:
Days of the week fall behind Earth due to the longer Sol, but they also change when Friday is omitted at the end of a Quarter
337 Earth days were observed to elapse in the 2020 weekday cycle. There were 7 week day transitions and 2 Quarter ends.
The next cycle began on the first Sol of the period of coincidence. The alignment of weekdays interval is in the range: (310 - 337)
To find the first day of a period of coincidence: Set up: SearchTerm(colon) and (colon)Alignment and J0036* or J0037*
The most recent End-Of-Quarter change occurred: … The search specified above gave 11 pages of results.
For current weather on Mars see:
***https://mars.nasa.gov/insight/weather/***
***Insight's weather info has been suspended and now is directing to msl*** <<-- Insight's mission is over (2022)
https://mars.nasa.gov/msl/weather/
Per SpaceNut: Here is another web page by NASA containing the latest news releases
https://mars.nasa.gov/news/?page=0&per_ … ope=Latest
All forum members are invited to post significant events for this day.
Events of interest will be ON Mars, or relate to Mars. Examples are launches, landings, discoveries
Standard Month in Mars Business Calendar Copyright ® 2023 NewMars.com Mars Society
Su Mo Tu We Th Fr Sa
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
Recruiting text may be found at the bottom of this post: http://newmars.com/forums/viewtopic.php … 57#p154257
Copyright the Mars Society All Rights Reserved
Month 1 of 24: First month of Quarter 1 and first month of Mars Year 39
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Place Holder for today's Calendar update:
[51.4792N, 0.0000E] 10/08/2026, 13:00:01 Europe/London
Object: Mars [open sky map]
RA 08h 34m 42.1s Dec +19° 52' 45.8" Appar J2000
Mag: 1.08 (Estimated: JPL) Const: Cancer
Current ID: 241998
Total number of registered users: 19,630
Total number of topics: 9,141
Total number of posts: 237,678
Newest registered user: Redfoot-2026
Registered users online: 1
Guests online: 371
Online: tahanson43206
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In this post we show output from Version 6 of our developing Prediction program for a Business Calendar for Mars.
It this version, we have attempted to improve the display of Sol "classification"
We are continuing to show the constellation above Airy Crater at the beginning of the Month.
We have discovered that in some months the same constellation will appear above Airy Crater at midnight. To deal with this we might be able to separate the readings into "East" and 'West". That decision has not yet been made. There may be another way to deal with this.
python3 BusinessCalendarForMarsV06.py
Mars Year 39 -- Month 1: Orion -- 5-Sol Rolling Forecast (Sols 8 to 12)
Sol 8 began at 11:16:03 UTC on October 08, 2026
Earth Date October 08 spans Sols 7 and 8--- Sol 8 of 668 ---
Mars Date: MY39 / Month 1 / Day 8
Constellation: Orion
Sol Classification: Sunday
Airy-0 Sol Start (Earth UTC): 2026-10-08 11:16:03 UTC
Airy-0 Sol End (Earth UTC): 2026-10-09 11:55:38 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 51.6% (2026-10-08) / 48.4% (Next Day)
--- Sol 9 of 668 ---
Mars Date: MY39 / Month 1 / Day 9
Constellation: Orion
Sol Classification: Monday
Airy-0 Sol Start (Earth UTC): 2026-10-09 11:55:38 UTC
Airy-0 Sol End (Earth UTC): 2026-10-10 12:35:14 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 49.0% (2026-10-09) / 51.0% (Next Day)
--- Sol 10 of 668 ---
Mars Date: MY39 / Month 1 / Day 10
Constellation: Orion
Sol Classification: Tuesday
Airy-0 Sol Start (Earth UTC): 2026-10-10 12:35:14 UTC
Airy-0 Sol End (Earth UTC): 2026-10-11 13:14:49 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 46.3% (2026-10-10) / 53.7% (Next Day)
--- Sol 11 of 668 ---
Mars Date: MY39 / Month 1 / Day 11
Constellation: Orion
Sol Classification: Wednesday
Airy-0 Sol Start (Earth UTC): 2026-10-11 13:14:49 UTC
Airy-0 Sol End (Earth UTC): 2026-10-12 13:54:24 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 43.6% (2026-10-11) / 56.4% (Next Day)
--- Sol 12 of 668 ---
Mars Date: MY39 / Month 1 / Day 12
Constellation: Orion
Sol Classification: Thursday
Airy-0 Sol Start (Earth UTC): 2026-10-12 13:54:24 UTC
Airy-0 Sol End (Earth UTC): 2026-10-13 14:33:59 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 40.9% (2026-10-12) / 59.1% (Next Day)
Mars Business Calendar Protocol | Airy-0 Mean Midnight | MY 39
The next major test for this new program will occur when an Earth day fits entirely inside a Martian Sol. That is predicted for Sol 24. in the physical calendar, this would show up as an empty cell with only the Earth date inside.
(th)
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===
Today on Mars: 0039/01/08 Sunday Days of the week OFFSET 4 with Earth. (count from Mars to Earth )
Sol 008 Business Month 01 First month of Quarter 1 of Year 39
Today on Earth: 2026/10/08 Thursday
>16
To see how this calendar works, we show the standard 28 day month at the bottom of this daily report.
There are 20 months of 28 Sols and 4 months of 27 Sols at the end of the four six-month quarters.
New Years Eve is extended to align the Business Calendar for Mars with the Astronomical calendar.
Business and Astronomical both start at zero (to the nanosecond) on New Year's Day.
This calendar has been in operation for two full Mars years (36 and 37). We are in Year 38
This calendar is NOT the Darian Calendar!
Per http://www-mars.lmd.jussieu.fr/mars/tim … _time.html also see: in-the-sky.org for opposition/perigee/aphelion
Martian Year: 39 Martian Astronomical Interval in 12 interval format: 1 <<== The Astronomical interval
Check Longitude: the interval will increment when longitude reaches 30 degrees
===
Solar Longitude: 003.7 Sol Number: 008 Change in degrees is +.5 Julian date is: J0039008
Solar Longitude: 003.2 Sol Number: 007 Change in degrees is +.5 Julian date is: J0039007
Solar Longitude: 002.7 Sol Number: 006 Change in degrees is +.5 Julian date is: J0039006
#6>
Note that Solar Longitude measurement varies as a function of location in orbit. Ls 0 is the moment when the Sun appears to transit from one hemisphere to the other. Update from Mars.NASA.gov (The Sun crosses the equator of Mars (Vernal Equinox)). The transition itself is a function of the tilt of an object with respect to the Solar plane. Per squarewidget.com, Hipparchus created the celestial coordinate system we use today.
Note#2: https://theskylive.com/mars-tracker This web site shows the astronomical position of Mars as seen from Earth
Todo: At next Aphelion/Perihelion record the Mars date as J00##### (and set Search term)
Perihelion occurred in 2026 at Ls 251 on Sol 486 - Earth Date 2026/03/27 Next: (estimated) 2028/05/15
Perihelion occurred in 2024 at Ls 251 on Sol 485 - Earth Date 2024/05/08 Next: (estimated) 2026/03/06 (actual) 2026/03/26
Perihelion occurred in 2022 at Ls 251 on Sol 485 - Earth Date 2022/06/21 Next: (actual) 2024/05/08
Aphelion Earth Dates: Next: 2027/03/04 Earlier: 2025/04/16, 2023/05/30, 2021/07/12, 2019/08/25, 2017/10/07, 2015/11/20
Aphelion occurred at--- Ls 071 on Sol 152.
Aphelion occurred near Ls 070 on Sol 153 (per http://www.planetary.org)
Note#3: The computations below are dependent upon both the computations provided by the reference web site and by accuracy of recording of the time of observations. The calculations use tenths of hours. The Sun Distance needs to be captured at the moment the time increments to a given tenth.
Note on data below: The figure quoted after distance is a rate of progress along the orbital path [exact meaning to be determined]
Minus prefix means Mars is approaching the Sun. Plus prefix means Mars is moving away from the Sun.
The figure computed to the right of "Difference" is the rate of change of the distance to Sun. Increasing to Aphelion/Decreasing to Perihelion.
Aphelion of Mars is due March 04, 2027 Sol 151-152 Note velocity of Mars was 22.0 km/s nearing Aphelion (21.97 km/s)
Perhelion of Mars is due May, 2028 Sol 251 Note velocity of Mars was 26.5 km/s nearing Perihelion 2026/03/26
Mars passed through 0 Radial Distance on outbound leg Sol 633 of Year 38 2026/08/25 Solar Longitude is 341.1 (90 degrees season)
Mars will pass through 0 Radial Distance on inbound leg Sol 219 at longitude 71 270 degrees seasonal)
Conversion between seasons and physical frameworks: L_s = theta + 251 theta = L_s - 251
===
Distance: Mars >> Sun per theskylive.com: 234,480,342 km [23.4 km/s] Difference is +180492 <= +7521 km/hour at 12.0 on 10/08 (time 12:00) (24.0 hours)
Distance: Mars >> Sun per theskylive.com: 234,299,850 km [23.5 km/s] Difference is +181120 <= +7547 km/hour at 12.0 on 10/07 (time 12:00) (24.0 hours)
Distance: Mars >> Sun per theskylive.com: 234,118,730 km [23.5 km/s] Difference is +181788 <= +7575 km/hour at 12.0 on 10/06 (time 12:00) (24.0 hours)
>13
Velocity along the orbit is NOT the same thing as velocity change of the radial distance to the Sun. Both are shown in the section above.
Observation: The sky view is ** filled ** with objects and some have been recorded and given identification by humans or their robot assistants
And! ** All ** the location assignments are from the perspective of Earth. The entire catalog needs to be adjusted when inter-stellar travel begins
The work that lies ahead for the astronomical community is daunting - there is work ahead for centuries
2022/01/19 - All current (existing) stellar catalogs are computed with reference to the Earth. Another civilization would use it's planet as reference.
Perhaps a Milky Way frame of reference will become necessary at some point. The Earth is as good a Zero point as any, for humans.
=== Mars is in Regular movement as seen from Earth.
Mars is in cancer – we in NewMars have an opportunity to visit some of the stars in Cancer during this period
Next ahead: galaxy just below path: PGC 1607316 RA 8h 35m 31.4s
14>
Zoom Out Capability As a general observation ... I've become increasingly interested in knowing what the larger view of the sky might be like.
The site: theskylive.com does a terrific job of matching the view from Earth towards Mars, against a background of actual astronomical plates.
I wish there were a way (or rather, I wish I ** knew ** about a way that may exist) to enlarge the view until the entire galaxy is in view (Zoom out)
Update 2022/12/08 TheSkyLive.com provides a large view of selected objects: Select [Major Bodies] Then select [Information] in the body of interest
Update 2022/12/08 Scroll down to (body) Position and Finder Charts. Field of view is 50x30 degrees.
Light travel in one second is (about) 300,000 kilometers. The distance covered in one minute is about 18,000,000 kilometers. Estimated light times:
1:18,2:36,3:54,4:72,5:90,6:108,7:126,8:144,9:162,10:180,11:198,12:216,13:234,14:252,15:270,16:288,17:306,18:324, 19:342,20:360,21:378,22:396
Light travel time today is between 14 and 15 minutes. Communications delay would be 28+ minutes round trip.
=== Time estimate will change below 234 megaKm
Earth Distance in km: 2026/10/08 241,270,129 (decreasing)
Earth Distance in km: 2026/10/07 242,342,656 (decreasing)
Earth Distance in km: 2026/10/06 243,408,282 (decreasing)
>15
Maximum Earth-Mars distance is estimated to be 401 million kilometers (both at apogee and opposite vs Sun) Minimum is about 56 million kilometers
Mars and Earth were in Opposition (Earth center) in December of 2022. The date coincided with a (very rare) occultation of Mars by the Moon.
Mars and Earth were in Conjunction (Sun center) in November of 2023.
Mars and Earth appear to have been as close as they will get in Year 36. 81,454,323 kilometers on J0036644 Time: 4.53 minutes - 9 minutes round trip
In his online interview with Dr. Zubrin at the 2020 Mars Conference, Elon Musk reminded the audience that communications with Mars will necessarily include an intermediary station to handle traffic when the Sun is between Mars and Earth. Communications delays in that circumstance will increase due to the extra distance to be covered. Mr. Musk indicated he expects such communication will be handled by laser. Location would be optimum at poles of solar plane.
This web site offers an online model of the solar system: www.solarsystemscope.com
This web site offers an online orrery view of the Solar System: https://www.theplanetstoday.com/
===
Sol 008 is in Month 01 of a Proposed 24 month calendar. See Post 19 of Holidays topic for a summary. <<< 37 is skip day on Mars
Month 01 extends from Sol 1 through 28. <<== There are 28 Sols in Month 01. See post 82 of Holidays topic for current details
Direct path to source: http://newmars.com/forums/viewtopic.php … 57#p154257
Sol 008 is Sunday in the Proposed Business calendar for Mars. Sol 667 Skip Day on Mars. Next is near 24 or 37 of Year 39
##
The Next New Year's on Mars will occur when Solar Longitude reaches 360 degrees. Year 38 started November 12, 2024 on Earth
Per www.planetary.org Year 36 started 2021/02/07 on Earth. Mars Year 37 began 2022/12/27 on Earth.
Days of the Week Alignment:
Days of the week fall behind Earth due to the longer Sol, but they also change when Friday is omitted at the end of a Quarter
337 Earth days were observed to elapse in the 2020 weekday cycle. There were 7 week day transitions and 2 Quarter ends.
The next cycle began on the first Sol of the period of coincidence. The alignment of weekdays interval is in the range: (310 - 337)
To find the first day of a period of coincidence: Set up: SearchTerm(colon) and (colon)Alignment and J0036* or J0037*
The most recent End-Of-Quarter change occurred: … The search specified above gave 11 pages of results.
For current weather on Mars see:
***https://mars.nasa.gov/insight/weather/***
***Insight's weather info has been suspended and now is directing to msl*** <<-- Insight's mission is over (2022)
https://mars.nasa.gov/msl/weather/
Per SpaceNut: Here is another web page by NASA containing the latest news releases
https://mars.nasa.gov/news/?page=0&per_ … ope=Latest
All forum members are invited to post significant events for this day.
Events of interest will be ON Mars, or relate to Mars. Examples are launches, landings, discoveries
Standard Month in Mars Business Calendar Copyright ® 2023 NewMars.com Mars Society
Su Mo Tu We Th Fr Sa
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
Recruiting text may be found at the bottom of this post: http://newmars.com/forums/viewtopic.php … 57#p154257
Copyright the Mars Society All Rights Reserved
Month 1 of 24: First month of Quarter 1 and first month of Mars Year 39
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Place Holder for today's Calendar update:
[51.4792N, 0.0000E] 10/09/2026, 13:00:09 Europe/London
Object: Mars [open sky map]
RA 08h 37m 03.0s Dec +19° 45' 18.7" Appar J2000
Mag: 1.06 (Estimated: JPL) Const: Cancer
Current ID: 242017
Total number of registered users: 19,630
Total number of topics: 9,143
Total number of posts: 237,697
Newest registered user: Redfoot-2026
Registered users online: 2
Guests online: 505
Online: RobertDyck, tahanson43206
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python3 BusinessCalendarForMarsV06.py
Sol 9 began at 11:55:38 UTC on October 09, 2026
Earth Date October 09 spans Sols 8 and 9
--- Sol 9 of 668 ---
Mars Date: MY39 / Month 1 / Day 9
Constellation: Orion
Sol Classification: Monday
Airy-0 Sol Start (Earth UTC): 2026-10-09 11:55:38 UTC
Airy-0 Sol End (Earth UTC): 2026-10-10 12:35:14 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 49.0% (2026-10-09) / 51.0% (Next Day)
--- Sol 10 of 668 ---
Mars Date: MY39 / Month 1 / Day 10
Constellation: Orion
Sol Classification: Tuesday
Airy-0 Sol Start (Earth UTC): 2026-10-10 12:35:14 UTC
Airy-0 Sol End (Earth UTC): 2026-10-11 13:14:49 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 46.3% (2026-10-10) / 53.7% (Next Day)
--- Sol 11 of 668 ---
Mars Date: MY39 / Month 1 / Day 11
Constellation: Orion
Sol Classification: Wednesday
Airy-0 Sol Start (Earth UTC): 2026-10-11 13:14:49 UTC
Airy-0 Sol End (Earth UTC): 2026-10-12 13:54:24 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 43.6% (2026-10-11) / 56.4% (Next Day)
--- Sol 12 of 668 ---
Mars Date: MY39 / Month 1 / Day 12
Constellation: Orion
Sol Classification: Thursday
Airy-0 Sol Start (Earth UTC): 2026-10-12 13:54:24 UTC
Airy-0 Sol End (Earth UTC): 2026-10-13 14:33:59 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 40.9% (2026-10-12) / 59.1% (Next Day)
--- Sol 13 of 668 ---
Mars Date: MY39 / Month 1 / Day 13
Constellation: Orion
Sol Classification: Friday
Airy-0 Sol Start (Earth UTC): 2026-10-13 14:33:59 UTC
Airy-0 Sol End (Earth UTC): 2026-10-14 15:13:35 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 38.3% (2026-10-13) / 61.7% (Next Day)
Mars Business Calendar Protocol | Airy-0 Mean Midnight | MY 39
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===
Today on Mars: 0039/01/09 Monday Days of the week OFFSET 4 with Earth. (count from Mars to Earth )
Sol 009 Business Month 01 First month of Quarter 1 of Year 39
Today on Earth: 2026/10/09 Friday
>16
To see how this calendar works, we show the standard 28 day month at the bottom of this daily report.
There are 20 months of 28 Sols and 4 months of 27 Sols at the end of the four six-month quarters.
New Years Eve is extended to align the Business Calendar for Mars with the Astronomical calendar.
Business and Astronomical both start at zero (to the nanosecond) on New Year's Day.
This calendar has been in operation for two full Mars years (36 and 37). We are in Year 38
This calendar is NOT the Darian Calendar!
Per http://www-mars.lmd.jussieu.fr/mars/tim … _time.html also see: in-the-sky.org for opposition/perigee/aphelion
Martian Year: 39 Martian Astronomical Interval in 12 interval format: 1 <<== The Astronomical interval
Check Longitude: the interval will increment when longitude reaches 30 degrees
===
Solar Longitude: 004.1 Sol Number: 009 Change in degrees is +.4 Julian date is: J0039009
Solar Longitude: 003.7 Sol Number: 008 Change in degrees is +.5 Julian date is: J0039008
Solar Longitude: 003.2 Sol Number: 007 Change in degrees is +.5 Julian date is: J0039007
#6>
Note that Solar Longitude measurement varies as a function of location in orbit. Ls 0 is the moment when the Sun appears to transit from one hemisphere to the other. Update from Mars.NASA.gov (The Sun crosses the equator of Mars (Vernal Equinox)). The transition itself is a function of the tilt of an object with respect to the Solar plane. Per squarewidget.com, Hipparchus created the celestial coordinate system we use today.
Note#2: https://theskylive.com/mars-tracker This web site shows the astronomical position of Mars as seen from Earth
Todo: At next Aphelion/Perihelion record the Mars date as J00##### (and set Search term)
Perihelion occurred in 2026 at Ls 251 on Sol 486 - Earth Date 2026/03/27 Next: (estimated) 2028/05/15
Perihelion occurred in 2024 at Ls 251 on Sol 485 - Earth Date 2024/05/08 Next: (estimated) 2026/03/06 (actual) 2026/03/26
Perihelion occurred in 2022 at Ls 251 on Sol 485 - Earth Date 2022/06/21 Next: (actual) 2024/05/08
Aphelion Earth Dates: Next: 2027/03/04 Earlier: 2025/04/16, 2023/05/30, 2021/07/12, 2019/08/25, 2017/10/07, 2015/11/20
Aphelion occurred at--- Ls 071 on Sol 152.
Aphelion occurred near Ls 070 on Sol 153 (per http://www.planetary.org)
Note#3: The computations below are dependent upon both the computations provided by the reference web site and by accuracy of recording of the time of observations. The calculations use tenths of hours. The Sun Distance needs to be captured at the moment the time increments to a given tenth.
Note on data below: The figure quoted after distance is a rate of progress along the orbital path [exact meaning to be determined]
Minus prefix means Mars is approaching the Sun. Plus prefix means Mars is moving away from the Sun.
The figure computed to the right of "Difference" is the rate of change of the distance to Sun. Increasing to Aphelion/Decreasing to Perihelion.
Aphelion of Mars is due March 04, 2027 Sol 151-152 Note velocity of Mars was 22.0 km/s nearing Aphelion (21.97 km/s)
Perhelion of Mars is due May, 2028 Sol 251 Note velocity of Mars was 26.5 km/s nearing Perihelion 2026/03/26
Mars passed through 0 Radial Distance on outbound leg Sol 633 of Year 38 2026/08/25 Solar Longitude is 341.1 (90 degrees season)
Mars will pass through 0 Radial Distance on inbound leg Sol 219 at longitude 71 270 degrees seasonal)
Conversion between seasons and physical frameworks: L_s = theta + 251 theta = L_s - 251
===
Distance: Mars >> Sun per theskylive.com: 234,660,197 km [23.4 km/s] Difference is +179855 <= +7494 km/hour at 12.0 on 10/09 (time 12:00) (24.0 hours)
Distance: Mars >> Sun per theskylive.com: 234,480,342 km [23.4 km/s] Difference is +180492 <= +7521 km/hour at 12.0 on 10/08 (time 12:00) (24.0 hours)
Distance: Mars >> Sun per theskylive.com: 234,299,850 km [23.5 km/s] Difference is +181120 <= +7547 km/hour at 12.0 on 10/07 (time 12:00) (24.0 hours)
>13
Velocity along the orbit is NOT the same thing as velocity change of the radial distance to the Sun. Both are shown in the section above.
Observation: The sky view is ** filled ** with objects and some have been recorded and given identification by humans or their robot assistants
And! ** All ** the location assignments are from the perspective of Earth. The entire catalog needs to be adjusted when inter-stellar travel begins
The work that lies ahead for the astronomical community is daunting - there is work ahead for centuries
2022/01/19 - All current (existing) stellar catalogs are computed with reference to the Earth. Another civilization would use it's planet as reference.
Perhaps a Milky Way frame of reference will become necessary at some point. The Earth is as good a Zero point as any, for humans.
=== Mars is in Regular movement as seen from Earth.
Mars is in cancer – we in NewMars have an opportunity to visit some of the stars in Cancer during this period
Next ahead: Bright star Magnitude 7.72 TYC 1395-2334-1 RA 8h 37m 37s
galaxy just below path: PGC 1607316 RA 8h 35m 31.4s Day 2 just past Mars
14>
Zoom Out Capability As a general observation ... I've become increasingly interested in knowing what the larger view of the sky might be like.
The site: theskylive.com does a terrific job of matching the view from Earth towards Mars, against a background of actual astronomical plates.
I wish there were a way (or rather, I wish I ** knew ** about a way that may exist) to enlarge the view until the entire galaxy is in view (Zoom out)
Update 2022/12/08 TheSkyLive.com provides a large view of selected objects: Select [Major Bodies] Then select [Information] in the body of interest
Update 2022/12/08 Scroll down to (body) Position and Finder Charts. Field of view is 50x30 degrees.
Light travel in one second is (about) 300,000 kilometers. The distance covered in one minute is about 18,000,000 kilometers. Estimated light times:
1:18,2:36,3:54,4:72,5:90,6:108,7:126,8:144,9:162,10:180,11:198,12:216,13:234,14:252,15:270,16:288,17:306,18:324, 19:342,20:360,21:378,22:396
Light travel time today is between 14 and 15 minutes. Communications delay would be 28+ minutes round trip.
=== Time estimate will change below 234 megaKm
Earth Distance in km: 2026/10/09 240,190,756 (decreasing)
Earth Distance in km: 2026/10/08 241,270,129 (decreasing)
Earth Distance in km: 2026/10/07 242,342,656 (decreasing)
>15
Maximum Earth-Mars distance is estimated to be 401 million kilometers (both at apogee and opposite vs Sun) Minimum is about 56 million kilometers
Mars and Earth were in Opposition (Earth center) in December of 2022. The date coincided with a (very rare) occultation of Mars by the Moon.
Mars and Earth were in Conjunction (Sun center) in November of 2023.
Mars and Earth appear to have been as close as they will get in Year 36. 81,454,323 kilometers on J0036644 Time: 4.53 minutes - 9 minutes round trip
In his online interview with Dr. Zubrin at the 2020 Mars Conference, Elon Musk reminded the audience that communications with Mars will necessarily include an intermediary station to handle traffic when the Sun is between Mars and Earth. Communications delays in that circumstance will increase due to the extra distance to be covered. Mr. Musk indicated he expects such communication will be handled by laser. Location would be optimum at poles of solar plane.
This web site offers an online model of the solar system: www.solarsystemscope.com
This web site offers an online orrery view of the Solar System: https://www.theplanetstoday.com/
===
Sol 009 is in Month 01 of a Proposed 24 month calendar. See Post 19 of Holidays topic for a summary. <<< 37 is skip day on Mars
Month 01 extends from Sol 1 through 28. <<== There are 28 Sols in Month 01. See post 82 of Holidays topic for current details
Direct path to source: http://newmars.com/forums/viewtopic.php … 57#p154257
Sol 009 is Monday in the Proposed Business calendar for Mars. Sol 667 Skip Day on Mars. Next is near 24 or 37 of Year 39
##
The Next New Year's on Mars will occur when Solar Longitude reaches 360 degrees. Year 38 started November 12, 2024 on Earth
Per www.planetary.org Year 36 started 2021/02/07 on Earth. Mars Year 37 began 2022/12/27 on Earth.
Days of the Week Alignment:
Days of the week fall behind Earth due to the longer Sol, but they also change when Friday is omitted at the end of a Quarter
337 Earth days were observed to elapse in the 2020 weekday cycle. There were 7 week day transitions and 2 Quarter ends.
The next cycle began on the first Sol of the period of coincidence. The alignment of weekdays interval is in the range: (310 - 337)
To find the first day of a period of coincidence: Set up: SearchTerm(colon) and (colon)Alignment and J0036* or J0037*
The most recent End-Of-Quarter change occurred: … The search specified above gave 11 pages of results.
For current weather on Mars see:
***https://mars.nasa.gov/insight/weather/***
***Insight's weather info has been suspended and now is directing to msl*** <<-- Insight's mission is over (2022)
https://mars.nasa.gov/msl/weather/
Per SpaceNut: Here is another web page by NASA containing the latest news releases
https://mars.nasa.gov/news/?page=0&per_ … ope=Latest
All forum members are invited to post significant events for this day.
Events of interest will be ON Mars, or relate to Mars. Examples are launches, landings, discoveries
Standard Month in Mars Business Calendar Copyright ® 2023 NewMars.com Mars Society
Su Mo Tu We Th Fr Sa
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
Recruiting text may be found at the bottom of this post: http://newmars.com/forums/viewtopic.php … 57#p154257
Copyright the Mars Society All Rights Reserved
Month 1 of 24: First month of Quarter 1 and first month of Mars Year 39
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Place Holder for today's Calendar update:
[51.4792N, 0.0000E] 10/10/2026, 13:00:01 Europe/London
Object: Mars [open sky map]
RA 08h 39m 23.1s Dec +19° 37' 47.8" Appar J2000
Mag: 1.05 (Estimated: JPL) Const: Cancer
Current ID: 242035
Total number of registered users: 19,630
Total number of topics: 9,145
Total number of posts: 237,720
Newest registered user: Redfoot-2026
Registered users online: 1
Guests online: 389
Online: tahanson43206
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python3 BusinessCalendarForMarsV06.py
Sol 10 began at 12:35:14 UTC on October 10, 2026
Earth Date October 10 spans Sols 9 and 10
--- Sol 10 of 668 ---
Mars Date: MY39 / Month 1 / Day 10
Constellation: Orion
Sol Classification: Tuesday
Airy-0 Sol Start (Earth UTC): 2026-10-10 12:35:14 UTC
Airy-0 Sol End (Earth UTC): 2026-10-11 13:14:49 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 46.3% (2026-10-10) / 53.7% (Next Day)
--- Sol 11 of 668 ---
Mars Date: MY39 / Month 1 / Day 11
Constellation: Orion
Sol Classification: Wednesday
Airy-0 Sol Start (Earth UTC): 2026-10-11 13:14:49 UTC
Airy-0 Sol End (Earth UTC): 2026-10-12 13:54:24 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 43.6% (2026-10-11) / 56.4% (Next Day)
--- Sol 12 of 668 ---
Mars Date: MY39 / Month 1 / Day 12
Constellation: Orion
Sol Classification: Thursday
Airy-0 Sol Start (Earth UTC): 2026-10-12 13:54:24 UTC
Airy-0 Sol End (Earth UTC): 2026-10-13 14:33:59 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 40.9% (2026-10-12) / 59.1% (Next Day)
--- Sol 13 of 668 ---
Mars Date: MY39 / Month 1 / Day 13
Constellation: Orion
Sol Classification: Friday
Airy-0 Sol Start (Earth UTC): 2026-10-13 14:33:59 UTC
Airy-0 Sol End (Earth UTC): 2026-10-14 15:13:35 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 38.3% (2026-10-13) / 61.7% (Next Day)
--- Sol 14 of 668 ---
Mars Date: MY39 / Month 1 / Day 14
Constellation: Orion
Sol Classification: Saturday
Airy-0 Sol Start (Earth UTC): 2026-10-14 15:13:35 UTC
Airy-0 Sol End (Earth UTC): 2026-10-15 15:53:10 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 35.6% (2026-10-14) / 64.4% (Next Day)
Mars Business Calendar Protocol | Airy-0 Mean Midnight | MY 39
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===
Today on Mars: 0039/01/10 Tuesday Days of the week OFFSET 4 with Earth. (count from Mars to Earth )
Sol 010 Business Month 01 First month of Quarter 1 of Year 39
Today on Earth: 2026/10/10 Saturday
>16
To see how this calendar works, we show the standard 28 day month at the bottom of this daily report.
There are 20 months of 28 Sols and 4 months of 27 Sols at the end of the four six-month quarters.
New Years Eve is extended to align the Business Calendar for Mars with the Astronomical calendar.
Business and Astronomical both start at zero (to the nanosecond) on New Year's Day.
This calendar has been in operation for two full Mars years (36 and 37). We are in Year 38
This calendar is NOT the Darian Calendar!
Per http://www-mars.lmd.jussieu.fr/mars/tim … _time.html also see: in-the-sky.org for opposition/perigee/aphelion
Martian Year: 39 Martian Astronomical Interval in 12 interval format: 1 <<== The Astronomical interval
Check Longitude: the interval will increment when longitude reaches 30 degrees
===
Solar Longitude: 004.6 Sol Number: 010 Change in degrees is +.5 Julian date is: J0039010
Solar Longitude: 004.1 Sol Number: 009 Change in degrees is +.4 Julian date is: J0039009
Solar Longitude: 003.7 Sol Number: 008 Change in degrees is +.5 Julian date is: J0039008
#6>
Note that Solar Longitude measurement varies as a function of location in orbit. Ls 0 is the moment when the Sun appears to transit from one hemisphere to the other. Update from Mars.NASA.gov (The Sun crosses the equator of Mars (Vernal Equinox)). The transition itself is a function of the tilt of an object with respect to the Solar plane. Per squarewidget.com, Hipparchus created the celestial coordinate system we use today.
Note#2: https://theskylive.com/mars-tracker This web site shows the astronomical position of Mars as seen from Earth
Todo: At next Aphelion/Perihelion record the Mars date as J00##### (and set Search term)
Perihelion occurred in 2026 at Ls 251 on Sol 486 - Earth Date 2026/03/27 Next: (estimated) 2028/05/15
Perihelion occurred in 2024 at Ls 251 on Sol 485 - Earth Date 2024/05/08 Next: (estimated) 2026/03/06 (actual) 2026/03/26
Perihelion occurred in 2022 at Ls 251 on Sol 485 - Earth Date 2022/06/21 Next: (actual) 2024/05/08
Aphelion Earth Dates: Next: 2027/03/04 Earlier: 2025/04/16, 2023/05/30, 2021/07/12, 2019/08/25, 2017/10/07, 2015/11/20
Aphelion occurred at--- Ls 071 on Sol 152.
Aphelion occurred near Ls 070 on Sol 153 (per http://www.planetary.org)
Note#3: The computations below are dependent upon both the computations provided by the reference web site and by accuracy of recording of the time of observations. The calculations use tenths of hours. The Sun Distance needs to be captured at the moment the time increments to a given tenth.
Note on data below: The figure quoted after distance is a rate of progress along the orbital path [exact meaning to be determined]
Minus prefix means Mars is approaching the Sun. Plus prefix means Mars is moving away from the Sun.
The figure computed to the right of "Difference" is the rate of change of the distance to Sun. Increasing to Aphelion/Decreasing to Perihelion.
Aphelion of Mars is due March 04, 2027 Sol 151-152 Note velocity of Mars was 22.0 km/s nearing Aphelion (21.97 km/s)
Perhelion of Mars is due May, 2028 Sol 251 Note velocity of Mars was 26.5 km/s nearing Perihelion 2026/03/26
Mars passed through 0 Radial Distance on outbound leg Sol 633 of Year 38 2026/08/25 Solar Longitude is 341.1 (90 degrees season)
Mars will pass through 0 Radial Distance on inbound leg Sol 219 at longitude 71 270 degrees seasonal)
Conversion between seasons and physical frameworks: L_s = theta + 251 theta = L_s - 251
===
Distance: Mars >> Sun per theskylive.com: 234,839,350 km [23.4 km/s] Difference is +179153 <= +7465 km/hour at 12.0 on 10/10 (time 12:00) (24.0 hours)
Distance: Mars >> Sun per theskylive.com: 234,660,197 km [23.4 km/s] Difference is +179855 <= +7494 km/hour at 12.0 on 10/09 (time 12:00) (24.0 hours)
Distance: Mars >> Sun per theskylive.com: 234,480,342 km [23.4 km/s] Difference is +180492 <= +7521 km/hour at 12.0 on 10/08 (time 12:00) (24.0 hours)
>13
Velocity along the orbit is NOT the same thing as velocity change of the radial distance to the Sun. Both are shown in the section above.
Observation: The sky view is ** filled ** with objects and some have been recorded and given identification by humans or their robot assistants
And! ** All ** the location assignments are from the perspective of Earth. The entire catalog needs to be adjusted when inter-stellar travel begins
The work that lies ahead for the astronomical community is daunting - there is work ahead for centuries
2022/01/19 - All current (existing) stellar catalogs are computed with reference to the Earth. Another civilization would use it's planet as reference.
Perhaps a Milky Way frame of reference will become necessary at some point. The Earth is as good a Zero point as any, for humans.
=== Mars is in Regular movement as seen from Earth.
Mars is in cancer – we in NewMars have an opportunity to visit some of the stars in Cancer during this period
Next ahead: 3 bright stars across path HIP 42578 RA 8h 40m 43.2s
Bright star Magnitude 7.72 TYC 1395-2334-1 RA 8h 37m 37s Day 2 sitting on 6 hours marker
14>
Zoom Out Capability As a general observation ... I've become increasingly interested in knowing what the larger view of the sky might be like.
The site: theskylive.com does a terrific job of matching the view from Earth towards Mars, against a background of actual astronomical plates.
I wish there were a way (or rather, I wish I ** knew ** about a way that may exist) to enlarge the view until the entire galaxy is in view (Zoom out)
Update 2022/12/08 TheSkyLive.com provides a large view of selected objects: Select [Major Bodies] Then select [Information] in the body of interest
Update 2022/12/08 Scroll down to (body) Position and Finder Charts. Field of view is 50x30 degrees.
Light travel in one second is (about) 300,000 kilometers. The distance covered in one minute is about 18,000,000 kilometers. Estimated light times:
1:18,2:36,3:54,4:72,5:90,6:108,7:126,8:144,9:162,10:180,11:198,12:216,13:234,14:252,15:270,16:288,17:306,18:324, 19:342,20:360,21:378,22:396
Light travel time today is between 14 and 15 minutes. Communications delay would be 28+ minutes round trip.
=== Time estimate will change below 234 megaKm
Earth Distance in km: 2026/10/09 239,104,924 (decreasing)
Earth Distance in km: 2026/10/09 240,190,756 (decreasing)
Earth Distance in km: 2026/10/08 241,270,129 (decreasing)
>15
Maximum Earth-Mars distance is estimated to be 401 million kilometers (both at apogee and opposite vs Sun) Minimum is about 56 million kilometers
Mars and Earth were in Opposition (Earth center) in December of 2022. The date coincided with a (very rare) occultation of Mars by the Moon.
Mars and Earth were in Conjunction (Sun center) in November of 2023.
Mars and Earth appear to have been as close as they will get in Year 36. 81,454,323 kilometers on J0036644 Time: 4.53 minutes - 9 minutes round trip
In his online interview with Dr. Zubrin at the 2020 Mars Conference, Elon Musk reminded the audience that communications with Mars will necessarily include an intermediary station to handle traffic when the Sun is between Mars and Earth. Communications delays in that circumstance will increase due to the extra distance to be covered. Mr. Musk indicated he expects such communication will be handled by laser. Location would be optimum at poles of solar plane.
This web site offers an online model of the solar system: www.solarsystemscope.com
This web site offers an online orrery view of the Solar System: https://www.theplanetstoday.com/
===
Sol 010 is in Month 01 of a Proposed 24 month calendar. See Post 19 of Holidays topic for a summary. <<< 37 is skip day on Mars
Month 01 extends from Sol 1 through 28. <<== There are 28 Sols in Month 01. See post 82 of Holidays topic for current details
Direct path to source: http://newmars.com/forums/viewtopic.php … 57#p154257
Sol 010 is Tuesday in the Proposed Business calendar for Mars. Sol 667 Skip Day on Mars. Next is near 24 or 37 of Year 39
##
The Next New Year's on Mars will occur when Solar Longitude reaches 360 degrees. Year 38 started November 12, 2024 on Earth
Per www.planetary.org Year 36 started 2021/02/07 on Earth. Mars Year 37 began 2022/12/27 on Earth.
Days of the Week Alignment:
Days of the week fall behind Earth due to the longer Sol, but they also change when Friday is omitted at the end of a Quarter
337 Earth days were observed to elapse in the 2020 weekday cycle. There were 7 week day transitions and 2 Quarter ends.
The next cycle began on the first Sol of the period of coincidence. The alignment of weekdays interval is in the range: (310 - 337)
To find the first day of a period of coincidence: Set up: SearchTerm(colon) and (colon)Alignment and J0036* or J0037*
The most recent End-Of-Quarter change occurred: … The search specified above gave 11 pages of results.
For current weather on Mars see:
***https://mars.nasa.gov/insight/weather/***
***Insight's weather info has been suspended and now is directing to msl*** <<-- Insight's mission is over (2022)
https://mars.nasa.gov/msl/weather/
Per SpaceNut: Here is another web page by NASA containing the latest news releases
https://mars.nasa.gov/news/?page=0&per_ … ope=Latest
All forum members are invited to post significant events for this day.
Events of interest will be ON Mars, or relate to Mars. Examples are launches, landings, discoveries
Standard Month in Mars Business Calendar Copyright ® 2023 NewMars.com Mars Society
Su Mo Tu We Th Fr Sa
1 2 3 4 5 6 7
8 9 10 11 12 13 14
15 16 17 18 19 20 21
22 23 24 25 26 27 28
Recruiting text may be found at the bottom of this post: http://newmars.com/forums/viewtopic.php … 57#p154257
Copyright the Mars Society All Rights Reserved
Month 1 of 24: First month of Quarter 1 and first month of Mars Year 39
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Place Holder for today's Calendar update:
[51.4792N, 0.0000E] 10/11/2026, 13:00:07 Europe/London
Object: Mars [open sky map]
RA 08h 41m 42.4s Dec +19° 30' 13.0" Appar J2000
Mag: 1.06 (Estimated: JPL) Const: Cancer
Current ID: 242049
Total number of registered users: 19,630
Total number of topics: 9,145
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This run of the Calendar Predictor was run at 12:54 UTC, while Sol 10 was still in effect on Mars.
python3 BusinessCalendarForMarsV06.py
Sol 10 began at 12:35:14 UTC on October 10, 2026
Earth Date October 10 spans Sols 9 and 10
--- Sol 10 of 668 ---
Mars Date: MY39 / Month 1 / Day 10
Constellation: Orion
Sol Classification: Tuesday
Airy-0 Sol Start (Earth UTC): 2026-10-10 12:35:14 UTC
Airy-0 Sol End (Earth UTC): 2026-10-11 13:14:49 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 46.3% (2026-10-10) / 53.7% (Next Day)
--- Sol 11 of 668 ---
Mars Date: MY39 / Month 1 / Day 11
Constellation: Orion
Sol Classification: Wednesday
Airy-0 Sol Start (Earth UTC): 2026-10-11 13:14:49 UTC
Airy-0 Sol End (Earth UTC): 2026-10-12 13:54:24 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 43.6% (2026-10-11) / 56.4% (Next Day)
--- Sol 12 of 668 ---
Mars Date: MY39 / Month 1 / Day 12
Constellation: Orion
Sol Classification: Thursday
Airy-0 Sol Start (Earth UTC): 2026-10-12 13:54:24 UTC
Airy-0 Sol End (Earth UTC): 2026-10-13 14:33:59 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 40.9% (2026-10-12) / 59.1% (Next Day)
--- Sol 13 of 668 ---
Mars Date: MY39 / Month 1 / Day 13
Constellation: Orion
Sol Classification: Friday
Airy-0 Sol Start (Earth UTC): 2026-10-13 14:33:59 UTC
Airy-0 Sol End (Earth UTC): 2026-10-14 15:13:35 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 38.3% (2026-10-13) / 61.7% (Next Day)
--- Sol 14 of 668 ---
Mars Date: MY39 / Month 1 / Day 14
Constellation: Orion
Sol Classification: Saturday
Airy-0 Sol Start (Earth UTC): 2026-10-14 15:13:35 UTC
Airy-0 Sol End (Earth UTC): 2026-10-15 15:53:10 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 35.6% (2026-10-14) / 64.4% (Next Day)
Mars Business Calendar Protocol | Airy-0 Mean Midnight | MY 39
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This run was launched at 13:15 UTC, after Sol 11 had started on Mars
python3 BusinessCalendarForMarsV06.py
Sol 11 began at 13:14:49 UTC on October 11, 2026
Earth Date October 11 spans Sols 10 and 11
--- Sol 11 of 668 ---
Mars Date: MY39 / Month 1 / Day 11
Constellation: Orion
Sol Classification: Wednesday
Airy-0 Sol Start (Earth UTC): 2026-10-11 13:14:49 UTC
Airy-0 Sol End (Earth UTC): 2026-10-12 13:54:24 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 43.6% (2026-10-11) / 56.4% (Next Day)
--- Sol 12 of 668 ---
Mars Date: MY39 / Month 1 / Day 12
Constellation: Orion
Sol Classification: Thursday
Airy-0 Sol Start (Earth UTC): 2026-10-12 13:54:24 UTC
Airy-0 Sol End (Earth UTC): 2026-10-13 14:33:59 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 40.9% (2026-10-12) / 59.1% (Next Day)
--- Sol 13 of 668 ---
Mars Date: MY39 / Month 1 / Day 13
Constellation: Orion
Sol Classification: Friday
Airy-0 Sol Start (Earth UTC): 2026-10-13 14:33:59 UTC
Airy-0 Sol End (Earth UTC): 2026-10-14 15:13:35 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 38.3% (2026-10-13) / 61.7% (Next Day)
--- Sol 14 of 668 ---
Mars Date: MY39 / Month 1 / Day 14
Constellation: Orion
Sol Classification: Saturday
Airy-0 Sol Start (Earth UTC): 2026-10-14 15:13:35 UTC
Airy-0 Sol End (Earth UTC): 2026-10-15 15:53:10 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 35.6% (2026-10-14) / 64.4% (Next Day)
--- Sol 15 of 668 ---
Mars Date: MY39 / Month 1 / Day 15
Constellation: Orion
Sol Classification: Sunday
Airy-0 Sol Start (Earth UTC): 2026-10-15 15:53:10 UTC
Airy-0 Sol End (Earth UTC): 2026-10-16 16:32:45 UTC
Sol Duration: 24.66 Hours (24h 39m 35s)
Earth UTC Overlap: 32.9% (2026-10-15) / 67.1% (Next Day)
Mars Business Calendar Protocol | Airy-0 Mean Midnight | MY 39
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Based upon observation that the Prediction program shows the Sol that is in effect at the instant the program is run, ChatGPT and I decided to add a line to the report clarifying when the program was run with respect to the time in Greenwich. We also clarified that the time measured in Mars hours is NOT the same as the time measured in Earth hours. The two planets rotate at different rates, which is why we have the longer Sol.
python3 BusinessCalendarForMarsV07.py
Prediction Generated (Earth UTC): 2026-10-11 13:40:10 UTC
Sol 11 began at 13:14:49 UTC on October 11, 2026
Earth Date October 11 spans Sols 10 and 11
--- Sol 11 of 668 ---
Mars Date: MY39 / Month 1 / Day 11
Constellation: Orion
Sol Classification: Wednesday
Airy-0 Sol Start (Earth UTC): 2026-10-11 13:14:49 UTC
Airy-0 Sol End (Earth UTC): 2026-10-12 13:54:24 UTC
Sol Duration (Mars Time): 24h 00m 00s
Sol Duration (Earth Time): 24h 39m 35.244s
Earth UTC Overlap: 43.6% (2026-10-11) / 56.4% (Next Day)
--- Sol 12 of 668 ---
Mars Date: MY39 / Month 1 / Day 12
Constellation: Orion
Sol Classification: Thursday
Airy-0 Sol Start (Earth UTC): 2026-10-12 13:54:24 UTC
Airy-0 Sol End (Earth UTC): 2026-10-13 14:33:59 UTC
Sol Duration (Mars Time): 24h 00m 00s
Sol Duration (Earth Time): 24h 39m 35.244s
Earth UTC Overlap: 40.9% (2026-10-12) / 59.1% (Next Day)
--- Sol 13 of 668 ---
Mars Date: MY39 / Month 1 / Day 13
Constellation: Orion
Sol Classification: Friday
Airy-0 Sol Start (Earth UTC): 2026-10-13 14:33:59 UTC
Airy-0 Sol End (Earth UTC): 2026-10-14 15:13:35 UTC
Sol Duration (Mars Time): 24h 00m 00s
Sol Duration (Earth Time): 24h 39m 35.244s
Earth UTC Overlap: 38.3% (2026-10-13) / 61.7% (Next Day)
--- Sol 14 of 668 ---
Mars Date: MY39 / Month 1 / Day 14
Constellation: Orion
Sol Classification: Saturday
Airy-0 Sol Start (Earth UTC): 2026-10-14 15:13:35 UTC
Airy-0 Sol End (Earth UTC): 2026-10-15 15:53:10 UTC
Sol Duration (Mars Time): 24h 00m 00s
Sol Duration (Earth Time): 24h 39m 35.244s
Earth UTC Overlap: 35.6% (2026-10-14) / 64.4% (Next Day)
--- Sol 15 of 668 ---
Mars Date: MY39 / Month 1 / Day 15
Constellation: Orion
Sol Classification: Sunday
Airy-0 Sol Start (Earth UTC): 2026-10-15 15:53:10 UTC
Airy-0 Sol End (Earth UTC): 2026-10-16 16:32:45 UTC
Sol Duration (Mars Time): 24h 00m 00s
Sol Duration (Earth Time): 24h 39m 35.244s
Earth UTC Overlap: 32.9% (2026-10-15) / 67.1% (Next Day)
Mars Business Calendar Protocol | Airy-0 Mean Midnight | MY 39
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===
Today on Mars: 0039/01/11 Wednesday Days of the week OFFSET 4 with Earth. (count from Mars to Earth )
Sol 011 Business Month 01 First month of Quarter 1 of Year 39
Today on Earth: 2026/10/11 Sunday
>16
To see how this calendar works, we show the standard 28 day month at the bottom of this daily report.
There are 20 months of 28 Sols and 4 months of 27 Sols at the end of the four six-month quarters.
New Years Eve is extended to align the Business Calendar for Mars with the Astronomical calendar.
Business and Astronomical both start at zero (to the nanosecond) on New Year's Day.
This calendar has been in operation for two full Mars years (36 and 37). We are in Year 38
This calendar is NOT the Darian Calendar!
Per http://www-mars.lmd.jussieu.fr/mars/tim … _time.html also see: in-the-sky.org for opposition/perigee/aphelion
Martian Year: 39 Martian Astronomical Interval in 12 interval format: 1 <<== The Astronomical interval
Check Longitude: the interval will increment when longitude reaches 30 degrees
===
Solar Longitude: 005.1 Sol Number: 011 Change in degrees is +.5 Julian date is: J0039011
Solar Longitude: 004.6 Sol Number: 010 Change in degrees is +.5 Julian date is: J0039010
Solar Longitude: 004.1 Sol Number: 009 Change in degrees is +.4 Julian date is: J0039009
#7>
Note that Solar Longitude measurement varies as a function of location in orbit. Ls 0 is the moment when the Sun appears to transit from one hemisphere to the other. Update from Mars.NASA.gov (The Sun crosses the equator of Mars (Vernal Equinox)). The transition itself is a function of the tilt of an object with respect to the Solar plane. Per squarewidget.com, Hipparchus created the celestial coordinate system we use today.
Note#2: https://theskylive.com/mars-tracker This web site shows the astronomical position of Mars as seen from Earth
Todo: At next Aphelion/Perihelion record the Mars date as J00##### (and set Search term)
Perihelion occurred in 2026 at Ls 251 on Sol 486 - Earth Date 2026/03/27 Next: (estimated) 2028/05/15
Perihelion occurred in 2024 at Ls 251 on Sol 485 - Earth Date 2024/05/08 Next: (estimated) 2026/03/06 (actual) 2026/03/26
Perihelion occurred in 2022 at Ls 251 on Sol 485 - Earth Date 2022/06/21 Next: (actual) 2024/05/08
Aphelion Earth Dates: Next: 2027/03/04 Earlier: 2025/04/16, 2023/05/30, 2021/07/12, 2019/08/25, 2017/10/07, 2015/11/20
Aphelion occurred at--- Ls 071 on Sol 152.
Aphelion occurred near Ls 070 on Sol 153 (per http://www.planetary.org)
Note#3: The computations below are dependent upon both the computations provided by the reference web site and by accuracy of recording of the time of observations. The calculations use tenths of hours. The Sun Distance needs to be captured at the moment the time increments to a given tenth.
Note on data below: The figure quoted after distance is a rate of progress along the orbital path [exact meaning to be determined]
Minus prefix means Mars is approaching the Sun. Plus prefix means Mars is moving away from the Sun.
The figure computed to the right of "Difference" is the rate of change of the distance to Sun. Increasing to Aphelion/Decreasing to Perihelion.
Aphelion of Mars is due March 04, 2027 Sol 151-152 Note velocity of Mars was 22.0 km/s nearing Aphelion (21.97 km/s)
Perhelion of Mars is due May, 2028 Sol 251 Note velocity of Mars was 26.5 km/s nearing Perihelion 2026/03/26
Mars passed through 0 Radial Distance on outbound leg Sol 633 of Year 38 2026/08/25 Solar Longitude is 341.1 (90 degrees season)
Mars will pass through 0 Radial Distance on inbound leg Sol 219 at longitude 71 270 degrees seasonal)
Conversion between seasons and physical frameworks: L_s = theta + 251 theta = L_s - 251
===
Distance: Mars >> Sun per theskylive.com: 235,017,855 km [23.4 km/s] Difference is +178505 <= +7438 km/hour at 12.0 on 10/11 (time 12:00) (24.0 hours)
Distance: Mars >> Sun per theskylive.com: 234,839,350 km [23.4 km/s] Difference is +179153 <= +7465 km/hour at 12.0 on 10/10 (time 12:00) (24.0 hours)
Distance: Mars >> Sun per theskylive.com: 234,660,197 km [23.4 km/s] Difference is +179855 <= +7494 km/hour at 12.0 on 10/09 (time 12:00) (24.0 hours)
>13
Velocity along the orbit is NOT the same thing as velocity change of the radial distance to the Sun. Both are shown in the section above.
Observation: The sky view is ** filled ** with objects and some have been recorded and given identification by humans or their robot assistants
And! ** All ** the location assignments are from the perspective of Earth. The entire catalog needs to be adjusted when inter-stellar travel begins
The work that lies ahead for the astronomical community is daunting - there is work ahead for centuries
2022/01/19 - All current (existing) stellar catalogs are computed with reference to the Earth. Another civilization would use it's planet as reference.
Perhaps a Milky Way frame of reference will become necessary at some point. The Earth is as good a Zero point as any, for humans.
=== Mars is in Regular movement as seen from Earth.
Mars is in cancer – we in NewMars have an opportunity to visit some of the stars in Cancer during this period
Next ahead: Star below path TYC 1395-1721-1 RA 8h 42m 6.5s
3 bright stars across path HIP 42578 RA 8h 40m 43.2s Day 2 above and ahead of Mars
14>
Zoom Out Capability As a general observation ... I've become increasingly interested in knowing what the larger view of the sky might be like.
The site: theskylive.com does a terrific job of matching the view from Earth towards Mars, against a background of actual astronomical plates.
I wish there were a way (or rather, I wish I ** knew ** about a way that may exist) to enlarge the view until the entire galaxy is in view (Zoom out)
Update 2022/12/08 TheSkyLive.com provides a large view of selected objects: Select [Major Bodies] Then select [Information] in the body of interest
Update 2022/12/08 Scroll down to (body) Position and Finder Charts. Field of view is 50x30 degrees.
Light travel in one second is (about) 300,000 kilometers. The distance covered in one minute is about 18,000,000 kilometers. Estimated light times:
1:18,2:36,3:54,4:72,5:90,6:108,7:126,8:144,9:162,10:180,11:198,12:216,13:234,14:252,15:270,16:288,17:306,18:324, 19:342,20:360,21:378,22:396
Light travel time today is between 14 and 15 minutes. Communications delay would be 28+ minutes round trip.
=== Time estimate will change below 234 megaKm
Earth Distance in km: 2026/10/11 238,012,337 (decreasing)
Earth Distance in km: 2026/10/10 239,104,924 (decreasing)
Earth Distance in km: 2026/10/09 240,190,756 (decreasing)
>15
Maximum Earth-Mars distance is estimated to be 401 million kilometers (both at apogee and opposite vs Sun) Minimum is about 56 million kilometers
Mars and Earth were in Opposition (Earth center) in December of 2022. The date coincided with a (very rare) occultation of Mars by the Moon.
Mars and Earth were in Conjunction (Sun center) in November of 2023.
Mars and Earth appear to have been as close as they will get in Year 36. 81,454,323 kilometers on J0036644 Time: 4.53 minutes - 9 minutes round trip
In his online interview with Dr. Zubrin at the 2020 Mars Conference, Elon Musk reminded the audience that communications with Mars will necessarily include an intermediary station to handle traffic when the Sun is between Mars and Earth. Communications delays in that circumstance will increase due to the extra distance to be covered. Mr. Musk indicated he expects such communication will be handled by laser. Location would be optimum at poles of solar plane.
This web site offers an online model of the solar system: www.solarsystemscope.com
This web site offers an online orrery view of the Solar System: https://www.theplanetstoday.com/
===
Sol 011 is in Month 01 of a Proposed 24 month calendar. See Post 19 of Holidays topic for a summary. <<< 37 is skip day on Mars
Month 01 extends from Sol 1 through 28. <<== There are 28 Sols in Month 01. See post 82 of Holidays topic for current details
Direct path to source: http://newmars.com/forums/viewtopic.php … 57#p154257
Sol 011 is Wednesday in the Proposed Business calendar for Mars. Sol 667 Skip Day on Mars. Next is near 24 or 37 of Year 39
##
The Next New Year's on Mars will occur when Solar Longitude reaches 360 degrees. Year 38 started November 12, 2024 on Earth
Per www.planetary.org Year 36 started 2021/02/07 on Earth. Mars Year 37 began 2022/12/27 on Earth.
Days of the Week Alignment:
Days of the week fall behind Earth due to the longer Sol, but they also change when Friday is omitted at the end of a Quarter
337 Earth days were observed to elapse in the 2020 weekday cycle. There were 7 week day transitions and 2 Quarter ends.
The next cycle began on the first Sol of the period of coincidence. The alignment of weekdays interval is in the range: (310 - 337)
To find the first day of a period of coincidence: Set up: SearchTerm(colon) and (colon)Alignment and J0036* or J0037*
The most recent End-Of-Quarter change occurred: … The search specified above gave 11 pages of results.
For current weather on Mars see:
***https://mars.nasa.gov/insight/weather/***
***Insight's weather info has been suspended and now is directing to msl*** <<-- Insight's mission is over (2022)
https://mars.nasa.gov/msl/weather/
Per SpaceNut: Here is another web page by NASA containing the latest news releases
https://mars.nasa.gov/news/?page=0&per_ … ope=Latest
All forum members are invited to post significant events for this day.
Events of interest will be ON Mars, or relate to Mars. Examples are launches, landings, discoveries
Standard Month in Mars Business Calendar Copyright ® 2023 NewMars.com Mars Society
Su Mo Tu We Th Fr Sa
1 2 3 4 5 6 7
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Month 1 of 24: First month of Quarter 1 and first month of Mars Year 39
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