Talk:Mars

Mars

Mars is a planet which is cold and scientists have been waiting to find more about it. some rover missons sent to mars have brought rock samples and they have shown such amazing samples that scientists doubt there is life on mars.

Ancient life on Mars

Since the red colour of Mars is due to rust compounds, is it not likely that the planet's ancient atmosphere once contained a large amount of free oxygen? And if so, wouldn't the existence of ancient life be the most likely explanation for this free oxygen? —Preceding unsigned comment added by 207.161.35.184 (talk • contribs)

I'm no planetologist, but my understanding (see just above) is that the oxygen is believed to have been derived from the photolysis of water. Cheers, --Plumbago 08:37, 4 October 2007 (UTC)

Photolysis is the main source (or the only one) for oxygen. In the soil the iron(II) is the main component not the iron(III) (and the concentration is much larger in several cm depth ) clearly stating that the martin atmosphere is not strongly oxidizing and that oxygen or hydroperoxide radicals are only a marginal effect in the atmosphere. A wide range photosynthetic driven biota would give other results. --Stone 08:40, 4 October 2007 (UTC)

Iron(II)/Iron(III)

The mößbauer spectroscopy indicates that most of the iron on mars is iron(II) not iron (III). In the drenches made by the rover wheels the ratio changed even more to iron(II). Even the red (iron(III)) regolite contains large amounts of iron(II) making it likely that the red colour is created by a thin layer of iron(III)oxide on top of everything. The pictures of the surfaces after the RAT instrument worked on them also shows that the red is not present in the interior of the rocks. This has implications on the atmospheric development and the possibility of oxygen in the atmosphere in the past. It should be mentioned in the article!--Stone 08:51, 4 October 2007 (UTC)

This is discussed in the "Mars surface color" entry. I have accordingly changed the current internal link of "reddish appearance" from "Iron(III) oxide" to "Mars surface color" Suniti 17 Dec 2007 (EST)

Mars' distance from earth

all I wanted to find was mars distance from Earth. It is not easy. Perhaps it changes? --Emesee 01:01, 13 October 2007 (UTC)

Yes it changes. Right now, according to an accurate program of mine, it is .889 astronomical units from the earth. This is about 133 Gm. Saros136 08:59, 13 October 2007 (UTC)

Absolutely—if you subtract Earth's orbital radius from Mars', you'll (approximately) get the minimum distance. If you add them, you'll (approximately) get the maximum distance. Ben Hocking ^{(talk|contribs)} 01:18, 13 October 2007 (UTC)

See http://www.heavens-above.com/planetsummary.asp. Range (AU) 0.591, now. 82.163.24.100 (talk) 13:03, 14 December 2007 (UTC)

Good catch. Mars is approaching a minimum, on Dec 18 at 88.2 Gm (.589 AU) it won't be this close until April 29, 2016 Saros136 (talk) 16:52, 14 December 2007 (UTC)

Temperature discrepancy

The info box lists the high/low temps as -85C and -5C, while in the article it says -140C and 20C. Is this somehow correct, or a mistake? --24.11.104.84 18:39, 7 November 2007 (UTC)

Hmmm. They're both sourced. The source for the 20°C high is just an abstract. The abstract indicates an above-zero max, but doesn't specify how above zero. To read the full article, you have to pay. I'm not going to pay nine bucks to check it.

This source also says 20°C, and ESA says 27°C. I think the JPL source is just wrong. I'll leave it the infobox at -5 just in case I'm totally missing something here. --Elliskev 22:28, 7 November 2007 (UTC)

Selling

Hello, earthlings. Someone is selling Mars. He also sells the Moon! Can we start a section 'bout this? Loolylolly1997 (talk) 01:40, 19 December 2007 (UTC)

INCOMMING!!!!

Just seen on the news that a asteroid is due to hit Mars real shortly. Trying to get more info. IF confirmed, we may get hit by shrapnel from this impact. 65.163.112.128 (talk) 22:15, 21 December 2007 (UTC)

2007 WD5 and Horizons

1. Go to http://ssd.jpl.nasa.gov/horizons.cgi?find_body=1&body_group=sb&sstr=2007WD5
2. Make sure "Ephemeris Type" is set to Observer.
3. Click "Observer Location" and change to @mars (Mars (body center) [500@499]).
4. Click "Time Span" and set to 2008-01-29 to 2008-01-31 STEP 1 minute.
5. (if you want) Table Settings: remove 1,9,23,24. Make sure 20 (Obsrv range & rng rate) is checked.
6. Generate away.

Delta is the distance (in AU) from Mars. Deldot is the change in direction in KM/Sec. The closest distance is currently "2008-Jan-30 09:10" at .0003AU. But do keep in mind that the orbit of this object is not well determined.
Kheider (talk) 17:53, 21 December 2007 (UTC)