Cassini-Huygens III - Continued from previous

Shaun Barrett · 2005-02-10 23:05:37

Cindy:-

So I feel it's incorrect to say "Saturn is a blue planet"...it's only partly blue apparently. And all the more lovely for it.

Thanks, REB and Cindy for that discussion and for the quotes. It's made the issue much clearer.

LtlPhysics:-

Does this mean that every planet with an appreciable atmosphere always scatters radiation that is at least as energetic as blue light?

I think it depends to an extent on the constituents of the atmosphere you're talking about. Obviously dust on a planet like Mars, and even in places here on Earth of course, can permeate the air and absorb blue light, leaving a distinctly red hue to the sky.
But, all things being equal, white light travelling through an atmosphere will tend to have the shorter wavelength (blue) light preferentially scattered. The longer wavelength end of the visible spectrum (red) scatters less and penetrates better.
(This is why rear fog lights on our vehicles are red, because the red light is scattered less by water vapour in the air and penetrates more efficiently, enhancing the visibility of vehicles on the road ahead of us.)

Interestingly, though, I once read an article about Mars which suggested that, even if we were to create (re-create?) a 1 bar atmosphere of CO2 there, the sky would probably appear white rather than blue (! ). I've never seen a satisfactory explanation for this assertion and I'd be interested to see the rationale behind it.
???

LtlPhysics · 2005-02-10 23:51:07

Mars clearly has a wisp of an atmosphere, but I didn't figure it was appreciable enough to scatter blue light (or block nasty radiation).

What would the sky of Venus look like?

Yang Liwei Rocket · 2005-02-11 00:36:53

Mars clearly has a wisp of an atmosphere, but I didn't figure it was appreciable enough to scatter blue light (or block nasty radiation).
What would the sky of Venus look like?

Titan does look somewhat like Mars, but also has many formations in common with earth. As for Venus try this from NASA and Russian missions http://boojum.as.arizona.edu/~jill/NS10 … ...s05.jpg
http://ftp.seds.org/pub/images/planets/ … /globe.gif
http://nineplanets.org/pics/v13.jpg]htt … cs/v13.jpg
http://www.solarviews.com/cap/venus/ven … nusmar.htm
a quick look at Titan again

http://www.solarviews.com/cap/index/tit … itan1.html

LtlPhysics · 2005-02-11 01:42:23

I remember those Soviet probes. One of them that made it to the surface used a low-tech approach to keep the spacecraft working once it reached the ground. They spent some time exposing the entire lander to the vacuum of space, letting the probe get as cold as possible before entry.

Palomar · 2005-02-11 05:17:42

*Could we please keep this thread focused on Saturn, Saturn's moons and Titan/Huygens?

I understand a bit of overlap and swerve might be unavoidable, but it looks like discussions might now go truly off-topic.

For other planets and old missions pertaining to them (which is off-topic for this thread) -- use "Search" and continue in an old thread established for them or create a new one and continue there please.

Thanks.

--Cindy

REB · 2005-02-11 08:40:39

Cindy, Let me answer one question, and then we'll get back to Saturn. (Actually) there are some similarities between Titan and Venus.

LtlPhysics, above Venus' clouds, its sky is blue during the day. Below the clouds it is yellow. A balloon probe, floating above the clouds would send back some wonderful picture. I would like to see such a probe sent to all the gas giants, and Titan.

I was hoping Huygens would have snapped a couple of pictures above Titan's haze, and maybe even get Saturn in the frame.

Like Venus, Titan's atmosphere is clear and blue above the clouds/haze. What a wonderful picture would be to have Saturn floating in Titan's blue sky above the orange haze/clouds below.

As for the scattering of blue light by an atmosphere, if the atmosphere is clear and composed of small molecule gasses(I don’t know the exact size, but around 1 to 4 atoms).

The atmosphere thickness also plays. The thicker the atmosphere is, the more light it adsorbs, so it starts looking whiter(White light reflects all wavelength of light. Black adsorbs all wavelengths of light).

I guess it comes down to have much matter you have making up the atmosphere, be it gas or dust. The more matter, the more light rays are adsorbed.

Looking at Saturn, its atmosphere is mostly hydrogen and helium’s, with traces of other gasses (Its clouds are made of stuff like water and ammonia). This type of atmosphere will scatter blue light, above the clouds.

REB · 2005-02-11 12:36:06

http://saturn.jpl.nasa.gov/multimedia/i … 556]Storms on Saturn

http://saturn.jpl.nasa.gov/multimedia/i … ID=31621]I think I saw this planet on Space 1999

http://saturn.jpl.nasa.gov/multimedia/i … =31629]And this picture is just too cool!

Palomar · 2005-02-11 13:05:49

http://saturn.jpl.nasa.gov/multimedia/i … 556]Storms on Saturn
http://saturn.jpl.nasa.gov/multimedia/i … ID=31621]I think I saw this planet on Space 1999
http://saturn.jpl.nasa.gov/multimedia/i … =31629]And this picture is just too cool!

*Those are marvelous raw images, REB. I've not had such luck in combing through the RI, but glad you spotted those. So few adjectives to describe Saturn's overwhelming beauty. Looking at unrotated pics has its advantages, as the vantage point of the eye goes. :up: In the last one, it looks like Saturn's decided to "stand" on its rings for us, LOL.

http://saturn.jpl.nasa.gov/multimedia/i … 353]Tethys and Ithaca Chasma

A new image in. IC averages 60 miles wide, as much as 2 miles deep in some areas, and more than 620 miles long.

Wish we had another view of that crater, Odysseus.

--Cindy

P.S.: Interesting, in the first pic you posted, how the large oval storm has what appears to be "white" curving tapers before and after it. Wish we could get a better explanation of that.

Yang Liwei Rocket · 2005-02-14 13:43:35

Carolyn Porco talks about Saturn

http://www.space.com/businesstechnology … ...14.html

Carolyn Porco will give a lecture titled “In Orbit! The Voyage of Cassini to Saturn and its Moons.” Porco, of the Space Science Institute in Boulder, Colo., leads the imaging team for the Cassini spacecraft, which carried the Huygens probe - lecture on 18th of Feb

Yang Liwei Rocket · 2005-02-15 05:19:51

*Could we please keep this thread focused on Saturn, Saturn's moons and Titan/Huygens?
I understand a bit of overlap and swerve might be unavoidable, but it looks like discussions might now go truly off-topic.
For other planets and old missions pertaining to them (which is off-topic for this thread) -- use "Search" and continue in an old thread established for them or create a new one and continue there please.
Thanks.
--Cindy

Ok, I'll put Venus talk in another thread

More on Saturn and Titan

map of Titan's surface illustrates the regions that will be imaged by Cassini during the spacecraft's fourth (and third very close) flyby of the smoggy moon on February 15, 2005. At closest approach, Cassini is expected to pass approximately 1,580 kilometers (982 miles) above the moon’s surface.
The colored lines delineate the regions that will be imaged at differing resolutions. The lower resolution imaging sequences (outlined in blue) are designed to study the atmosphere, clouds, and surface in a variety of spectral filters.

http://ciclops.lpl.arizona.edu/media/ir … 1580_1.jpg

dazzling ring system, takes center stage in this stunning natural color mosaic which reveals the color and diversity present in this wonder of the solar system. Gaps, gravitational resonances and wave patterns are all present and the delicate color variations across the system are clearly visible.

This mosaic of six images covers a distance of approximately 62,000 kilometers along the ring plane, from a radius of 74,565 kilometers to 136,780 kilometers (46,333 to 84,991 miles) from the planet’s center.

http://ciclops.lpl.arizona.edu/media/ir … 1600_1.jpg

minute-long sound file covering about 4 hours of real time
http://sci.esa.int/science-e/www/object … ctid=36510
motion becomes slower and steadier later in the descent

Titan images from the Cassini-Huygens mothership here

http://saturn.jpl.nasa.gov/multimedia/i … ...987.jpg

http://saturn.jpl.nasa.gov/multimedia/i … ...951.jpg

http://saturn.jpl.nasa.gov/multimedia/i … ...712.jpg

:up:

alan · 2005-02-15 08:36:14

Make sure your dog isn't in the room when you play that sound file

Palomar · 2005-02-15 08:44:44

*Thanks for those links, YL Rocket. I'll listen to the sound file later (I have a cold, and my ears are popping rather badly today; and the last Titan-related sound file I heard, OUCH).

And those rings...yep, dazzling.

http://saturn.jpl.nasa.gov/multimedia/i … 355]Vortex Flow

Oh god I want to see those movies they're making as they're tracking storms and etc. Dynamic and ever-changing...

Wish we'd get an image or two of lightning (regardless of Cassini instrument type).

-*-

http://saturn.jpl.nasa.gov/multimedia/i … D=1356]Not just another rings and moon pic

Lots of details about the rings in the caption.

Several thin ringlets comprising the F ring are nicely visible here, and the bright core of the ring displays a few twisted knots. Perhaps less noticeable are kinks in one of the thin ringlets of material visible within the Encke Gap near the upper left corner. The outer edge of the A ring appears notably brighter than the ring material on the other side of the narrow Keeler Gap. Finally, numerous gravitational resonances give the A ring a grooved or striped appearance in this view.

Would like to know more about how those "knots" and "kinks" develop and maintain (to whatever degree they maintain).

--Cindy

Palomar · 2005-02-16 07:25:02

*Latest Titan flyby images rolling in (though not a lot of commentary). Also plans for Enceladus flyby on the 17th.

http://saturn.jpl.nasa.gov/news/events/ … .cfm]Titan 3 Flyby & Enceladus Info

http://saturn.jpl.nasa.gov/multimedia/i … 7]Close-up of Titan

A caption at the homepage says (paraphrasing in my own words) this is the 4th time Cassini has buzzed Titan in 7 months. Cassini's radar instrument was switched on during Flyby 3. New areas of Titan have been imaged, along with additional images of previous areas. Cassini was turned away from our direction initially, but in the late afternoon of Feb 15 would be facing our direction again and transmitting images and info. :up:

--Cindy

REB · 2005-02-16 08:08:51

http://saturn.jpl.nasa.gov/multimedia/i … 194]Clouds have picked up at the pole.

Perhaps that is the source of the methane rain? I wonder how far from the poles the clouds will extend? I am curious if this pole is warming up, causing an increase in methane clouds. Eventually they’ll extend closer to the equator?

Palomar · 2005-02-16 08:27:18

http://saturn.jpl.nasa.gov/multimedia/i … 194]Clouds have picked up at the pole.
Perhaps that is the source of the methane rain? I wonder how far from the poles the clouds will extend? I am curious if this pole is warming up, causing an increase in methane clouds. Eventually they’ll extend closer to the equator?

*Those images are from Titan Flybys 1 and 2. Will be interesting to see what further information regarding the clouds and weather come from Flyby #3. Is two months since the most recent Flyby, so that only increases the anticipation -- more clouds or no?

And I sure hope they figure out the methane mystery (source) soon.

--Cindy

Yang Liwei Rocket · 2005-02-16 11:41:34

This looks very near
Like it almost crashed into the world of Titan

of course not, just skimming above the Stratosphere and Thermosphere

http://ciclops.lpl.arizona.edu/media/ir … 1759_1.jpg
image was taken during Cassini's third close approach to Titan on the 15th of February

Observed DISR Spectra on Titan
http://sci.esa.int/science-e-media/img/ … screen.jpg
Quote:
During the Huygens descent to the surface of Titan the DISR instrument recorded visible and infrared spectra (the change in the amount of light with varying colour or wavelength) of the ambient sunlight which is absorbed, diffused, and reflected by both the surface and the atmosphere. The figure shows spectra obtained by the Downward Looking Infrared Spectrometer at three altitudes: 150 km, 500 m and 20 m above the surface.

http://sci.esa.int/science-e/www/object … ctid=36536

processed sounds
http://planetary.org/sounds/huygens_sou … ounds.html

image was taken during Cassini's third close approach

http://ciclops.lpl.arizona.edu/media/ir … 1756_1.jpg

Saturn's complex rings are both an intriguing scientific puzzle and a supreme natural wonder. This view shows, from upper right to lower left, the thin C ring, multi-toned B ring, the dark Cassini Division, the A ring and narrow F ring.
At bottom, Mimas (398 kilometers, 247 miles across) orbits about 45,000 kilometers (28,000 miles) beyond the bright core of the F ring. The little moon is heavily cratered and is thought to be largely composed of water ice. The bright speck just outside of (below) the F ring is the shepherd moon Pandora (84 kilometers, 52 miles across).
http://ciclops.lpl.arizona.edu/media/dr … 1572_1.jpg

Palomar · 2005-02-16 12:29:02

http://www.space.com/scienceastronomy/0 … tml]Bright lights, eerie "heartbeat" at Saturn

*Incident dated January 2004 when Cassini-Huygens was still en-route to Saturn. However, the study includes past and current participation by Cassini.

An audio file of Saturn's auroral sounds is available through a link.

Includes a brief run-down of characteristics in Saturnian aurorae -- on Saturn, they can endure for days. Also, check out the middle characteristic...variable, wow.

--Cindy

P.S.: Check out illustration regarding Saturn's magnetosphere and magnetotail.

alan · 2005-02-16 19:22:05

Huge crater in radar image.

http://saturn.jpl.nasa.gov/home/index.c … /index.cfm

Palomar · 2005-02-16 21:24:43

Huge crater in radar image.

*Wow! Thanks Alan -- that's rolled in since I've last been online.

I'm going to link http://saturn.jpl.nasa.gov/multimedia/i … 2]directly to the image (your link goes to the C-H homepage, which constantly updates and pushes older images into the "Latest from Saturn" section; eventually it won't be viewable there).

Circus Maximus, huh? Out diameter aprox 273 miles.

It resembles a large crater or part of a ringed basin, either of which could be formed when a comet or asteroid tens of kilometers in size slammed into Titan. This is the first impact feature identified in radar images of Titan.

Says Titan's surface appears "very young" in comparison to other Saturnian moons. Discusses patterns of brightness in connection with the topography.

In Titan's case, debris raining down from the atmosphere or other geologic processes may mask or remove the craters

Amazing! Wonderful way to cap off a fruitful and rewarding day.

--Cindy

GraemeSkinner · 2005-02-17 00:32:17

http://www.space.com/scienceastronomy/0 … tml]Bright lights, eerie "heartbeat" at Saturn
*Incident dated January 2004 when Cassini-Huygens was still en-route to Saturn. However, the study includes past and current participation by Cassini.
An audio file of Saturn's auroral sounds is available through a link.
Includes a brief run-down of characteristics in Saturnian aurorae -- on Saturn, they can endure for days. Also, check out the middle characteristic...variable, wow.
--Cindy
P.S.: Check out illustration regarding Saturn's magnetosphere and magnetotail.

I wonder if you could observe one in the visible spectrum rather than UV; a series of images perhaps through a half decent telescope on Earth. Be interesting if another display flares up whilst Cassini is active.

Graeme

Yang Liwei Rocket · 2005-02-17 06:05:39

A big Crater on Titan ? That looks very good

Cassini's first close approach to Enceladus.
image was taken on February 16, 2005 with the narrow angle camera through a filter sensitive to wavelengths of polarized visible green light http://ciclops.lpl.arizona.edu/media/ir … 1835_1.jpg

another pic
http://saturn.jpl.nasa.gov/multimedia/i … 028182.jpg

GraemeSkinner · 2005-02-17 06:08:11

another pic
http://saturn.jpl.nasa.gov/multimedia/i … 028182.jpg

This link is showing as missing from the website, the first one looked good though.

Graeme

Yang Liwei Rocket · 2005-02-17 06:11:23

another pic
http://saturn.jpl.nasa.gov/multimedia/i … 028182.jpg
This link is showing as missing from the website, the first one looked good though.
Graeme

Ok try these, they should work better

http://ciclops.lpl.arizona.edu/media/ir … 1828_1.jpg
http://saturn.jpl.nasa.gov/multimedia/i … ...184.jpg
http://saturn.jpl.nasa.gov/multimedia/i … ...182.jpg

a bit of info on Crater Herschel

http://www.esa.int/SPECIALS/Cassini-Huy … M4E_0.html

:band:

GraemeSkinner · 2005-02-17 06:20:31

Ok try these, they should work better
http://ciclops.lpl.arizona.edu/media/ir … 1828_1.jpg
http://saturn.jpl.nasa.gov/multimedia/i … ...184.jpg
http://saturn.jpl.nasa.gov/multimedia/i … ...182.jpg

Excellent images, thanks for the links. The second one 'N00028184.jpg' looks like my car window on a frosty morning :;):

a bit of info on Crater Herschel
http://www.esa.int/SPECIALS/Cassini-Huy … M4E_0.html

It is the deathstar then is it?

Palomar · 2005-02-17 06:27:12

http://www.space.com/scienceastronomy/0 … tml]Bright lights, eerie "heartbeat" at Saturn
*Incident dated January 2004 when Cassini-Huygens was still en-route to Saturn. However, the study includes past and current participation by Cassini.
An audio file of Saturn's auroral sounds is available through a link.
Includes a brief run-down of characteristics in Saturnian aurorae -- on Saturn, they can endure for days. Also, check out the middle characteristic...variable, wow.
--Cindy
P.S.: Check out illustration regarding Saturn's magnetosphere and magnetotail.
I wonder if you could observe one in the visible spectrum rather than UV; a series of images perhaps through a half decent telescope on Earth. Be interesting if another display flares up whilst Cassini is active.
Graeme

*Hi Graeme. Yes, and I'm especially hoping they can figure out this particular mystery soon:

Some auroras at Saturn remain fixed as the planet rotates beneath them, as at Earth. But sometimes they move with the rotation of Saturn

:laugh: That's really something else.

Wow, am checking the pics of Enceladus which YL Rocket posted. Fantastic images -- looks like you can reach into the monitor and touch it (1st photo).

2nd pic...Many grooves. Am wondering about the height of the tallest "grooves"; the largest towards the upper part of the pic must surely be a mountain range? Or a range of very high hills...

3rd pic...looks like Enceladus needs to consult with a dermatologist! :-\ LOL.

Thanks for finding those, YL Rocket!

--Cindy

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Re: Cassini-Huygens III - Continued from previous

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Re: Cassini-Huygens III - Continued from previous

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Re: Cassini-Huygens III - Continued from previous

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Re: Cassini-Huygens III - Continued from previous

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Re: Cassini-Huygens III - Continued from previous

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Re: Cassini-Huygens III - Continued from previous

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Re: Cassini-Huygens III - Continued from previous

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Re: Cassini-Huygens III - Continued from previous

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Re: Cassini-Huygens III - Continued from previous

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