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#1 2007-01-31 08:58:35

Palomar
Member
From: USA
Registered: 2002-05-30
Posts: 9,734

Re: Neptune has 1000's of trojans?

http://www.space.com/scienceastronomy/0 … ojans.html

Neptune might have swarms of trojans -- perhaps 20 times that of Jupiter!  Trojans are asteroid-like objects, and those around Neptune might outnumber the asteroids in the Main Asteroid Belt!  :shock:   big_smile

Scientists hoping New Horizons spacecraft will be close enough to get a good photo of a Neptunian trojan in 2014.  Let's hope so.  smile

Neptune's trojans might be unique Solar System objects in their own right.

I always knew Neptune was groovy.   8)   This confirms it. 

--Cindy


We all know [i]those[/i] Venusians: Doing their hair in shock waves, smoking electrical coronas, wearing Van Allen belts and resting their tiny elbows on a Geiger counter...

--John Sladek (The New Apocrypha)

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#2 2022-03-21 15:06:03

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 8,892

Re: Neptune has 1000's of trojans?

Return to Neptune? The plans to send an orbiter to the elusive planet

https://www.planetary.org/articles/retu … tune-plans

Neptune Trojans (NTs) are swarms of outer solar system objects that lead/trail planet Neptune during its revolutions around the Sun. Observations indicate that NTs form a thick cloud of objects with a population perhaps ∼10 times more numerous than that of Jupiter Trojans and orbital inclinations reaching ∼25°. The high inclinations of NTs are indicative of capture instead of in situ formation. Here we study a model in which NTs were captured by Neptune during planetary migration when secondary resonances associated with the mean-motion commensurabilities between Uranus and Neptune swept over Neptune's Lagrangian points. This process, known as chaotic capture, is similar to that previously proposed to explain the origin of Jupiter's Trojans.
https://iopscience.iop.org/article/10.1 … 137/6/5003
We show that chaotic capture of planetesimals from an ≈35 Earth-mass planetesimal disk can produce a population of NTs that is at least comparable in number to that inferred from current observations. The large orbital inclinations of NTs are a natural outcome of chaotic capture. To obtain the ∼4:1 ratio between high- and low-inclination populations suggested by observations, planetary migration into a dynamically excited planetesimal disk may be required. The required stirring could have been induced by Pluto-sized and larger objects that have formed in the disk.


Neptune: Facts about the eighth planet from the sun
https://www.space.com/41-neptune-the-ot … ystem.html

Last edited by Mars_B4_Moon (2022-03-21 16:26:24)

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#3 2022-04-12 07:17:50

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 8,892

Re: Neptune has 1000's of trojans?

ESO Telescope Captures Surprising Changes In Neptune's Temperatures

http://spaceref.com/neptune/eso-telesco … tures.html

An international team of astronomers have used ground-based telescopes, including the European Southern Observatory's Very Large Telescope (ESO's VLT), to track Neptune's atmospheric temperatures over a 17-year period. They found a surprising drop in Neptune's global temperatures followed by a dramatic warming at its south pole.

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#4 2022-06-29 06:27:04

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 8,892

Re: Neptune has 1000's of trojans?

The Chinese National Space Agency is looking into a nuclear fission-powered mission to Neptune

https://www.planetary.org/articles/chin … ne-orbiter

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#5 2023-03-31 04:10:14

Mars_B4_Moon
Member
Registered: 2006-03-23
Posts: 8,892

Re: Neptune has 1000's of trojans?

Redness of Neptunian asteroids sheds light on early Solar System

https://www.spacedaily.com/reports/Redn … m_999.html

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#6 2023-04-02 03:51:28

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 3,352

Re: Neptune has 1000's of trojans?

The search for trojan exoplanets in binary star systems.
http://www.trojanplanets.appstate.edu/Intro.htm


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#7 2023-04-02 09:15:53

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Neptune has 1000's of trojans?

I'm surprised.  I did not think of that at all.

Done.


Done.

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#8 2023-04-03 15:03:01

Calliban
Member
From: Northern England, UK
Registered: 2019-08-18
Posts: 3,352

Re: Neptune has 1000's of trojans?

Void wrote:

I'm surprised.  I did not think of that at all.

Done.

Neither did I.  There is no analogue in our solar system today, but there may have been once.  There is speculation that Theia, the planet sized body that slammed into early Earth creating the moon, may have been a coorbital that formed in one of the Earth-Sun lagrange points.  These points are only stable so long as the mass of the third body is negligible compared to the other two.  If this ceases to be, then the gravitation attraction between the two bodies on the same orbit begins to influence the orbit of the primary.  It is estimated that Theia was about the size and mass of Mars, or ~10% Earth mass.  Closer to home, it suggests to me that the Earth-Moon L4 and L5 points would remain stable unless the mass of space stations located there exceeded 10% lunar mass.  It is hard to imagine that we would ever carve that much out of the moon.

A good place to look for a coirbital planet wouod be Sirius.  Sirius A is a lot brighter than our sun and Sirius B orbits at about the distance that Uranus orbits our sun.  Sirius B is massive enough to hold a coorbital larger than Jupiter.  So an Earth mass planet is certainly possible.  I am not sure how such a planet would have faired the Red Giant phase of Sirius B.  If it is as far from Sirius B as Uranus is from the sun, it is possible that it could have survived.
************************

Additional: Further investigation reveals that a Sirius B coorbital is not possible, due to the highly eliptical orbit of Sirius B.
https://metallicman.com/laoban4site/sir … rrestrials

In fact, Sirius is unlikely to have any planets closer than uts inner Oort Cloud.  An unpromissing place to look for life and probably not a good colonisation target.

Last edited by Calliban (2023-04-03 15:26:48)


"Plan and prepare for every possibility, and you will never act. It is nobler to have courage as we stumble into half the things we fear than to analyse every possible obstacle and begin nothing. Great things are achieved by embracing great dangers."

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#9 2023-04-03 19:21:49

Void
Member
Registered: 2011-12-29
Posts: 6,976

Re: Neptune has 1000's of trojans?

Quite an article.  I have not read it all, just got back from the gym and it is bedtime soon.

So, I will give you a horrible bedtime story.

This is entirely my opinion, so the woke should not complain, I am outing myself and my thinking.  I am not prescribing a way of life to anyone but I do believe I am doing a diagnosis.

Once upon a time supposedly men had some choice about women which they might mate with.  (Old style pronouns apply).

They often would choose between a balance of childlike features and fertility/ability to bear young.  For the poor, also a woman who could help with other burdens was also desirable, so for some men a stout woman was a good choice, presuming that this story might be true and men ever had such a choice.

There can be at least two reasons for selecting childlike features.  First, a male that is stupid enough to kill his children and childlike wife will be left wondering, if he has a mind at all, where his descendants are.  There are some of those even now, but generally not good for avoiding a Darwin award.

Child like features are in general, smaller body, generally shorter, large heat to body ratio can be good as that is how children are.  This head size thing could be what keeps the brain size large in the human species, (Or does not).  Higher voice is like a child.  Less violent in many close quarter situations, I think.  (Not sure).  Less body hair, typically is favored.

And then secondary sexual features are needed, such as apparently functional breasts, wider hips, baby making features.  As I have indicated from what I think I know even with Men the preferences can be juggled a bit.  Hips too wide, then the woman might not be able to run well enough from lions.  Hips too narrow, and she may die in childbirth if the child's head is from a line of big, brained people.

On the other hand many women want cave man traits from men they might get thrilled about.  They might exploit a less robust type when they are not fertile to leach protection and company from but when fertile they will seek out a knuckle dragger.  (On average, just like on average many men seek out a gracile female).

So, I think that this is the process control that helps human populations adapt to their current reality.

The very odd thing about the situation in the west is that women seem to be urgently trying to breed the human race back into the stone age, (On average), and yet the woke especially among them express great hatred for man and things masculine.  And yet these people as far as I can see and many of the people they collect (But do not tend to breed with), are really crappy at the masculine.  They tend to be wimpy men and if not wimps, then the breeders seem to be animals in that they do not have maturity.  I regard maturity in men as having power but not so much using it in a low sort of way.

I have done this post in this way because the article you linked pondered if the human race could be much more ancient than is supposed.  I suspect the answer is yes, and that it is possible for a world to fall from a flood of killer peoples, who are not adapted for anything but the stone age.  This would be a sort of flood.  A very advanced culture which had become exceptionally intelligent, might fall to such a problem.

But of course I don't know.

As per Trojan planets as you have speculated, I think you are correct.

It is interesting though that for binaries that are more regular there could be trojans, and also of course planets that orbit just one star or both stars.

And then there is Pluto.  Is that another possible thing?  The relationship between Neptune and Pluto, where even though Pluto crosses Neptunes orbit, it does so away from the typical planetary plain, I believe, and so they miss each other.

For a very large planet in a "Habitable Zone", it is felt that there might be moons of interest, but could there be a Pluto?  Could it be detected?

I would like it much more if Proxima-b were a collection of objects, not an oversized Earth.  Possibly it is a binary planet?  Maybe has a big moon?  Maybe a Pluto like companion?  Low odds I expect, but something to wonder about.

Done.

Last edited by Void (2023-04-03 19:57:37)


Done.

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