This little red planet is actually mainly red due to the Iron Oxide dust suspended in the atmosphere, Large areas of Mars do actually have red soil to though. Most of Mars is actually more of a butterscotch colour, yet you can also get areas which are more yellow or brown.
Mars is substantially smaller than earth and because of this has much lower gravity and therefore also less atmosphere. The smaller amount of atmosphere makes the surface pressure a lot less than on earth, having such a insubstantial atmosphere also stops the planet from retaining as much heat from the sun which consequently causes Mars to experience very low temperatures.
Mars is home to 2 of our Solar systems Largest features Valles Marineris and Olympus Mons.
Valles Marineris in Latin or Mariner's Valley in English is the Massive canyon system on Mars. Mariner's Valley is over 4000km long, 200km wide and up to 10km deep. The Rim of this Canyon in places is taller than Mt Everest. The Rift valleys on Earth are longer but not as deep or wide, There is also a Rift Valley on Venus that is comparable to Earth's.
Another cool Feature of Mars also has some spectacular Polar Ice caps that have an awesome spiral shape created by Katabatic winds due to the coriolis effect. The Polar ice caps contain mostly water ice but are also host to dry ice from the freezing Carbon Dioxide. The Southern Polar cap constantly has a layer of dry ice about 8 metres thick, while in the North deposits of dry ice usually only form in winter and get to be about 1 metre thick.
When the dry ice sublimes it creates great winds that gust off the poles up to 400km per hour.
Due to the thin atmosphere on Mars the air pressure at the surface is about 6 or 7 millibars compared to Earths 1000 millibars. Due to the low pressure being on Mars without a pressure suit would be extremely hazardous to say the least.
See Mars For Yourself.
When I first started being interested in space and the planets I thought having my own telescope was way out of my price range. Then I learnt that they aren't. A telescope capable of showing you the rings of Saturn or the galileo moons of Jupiter, even the polar caps of Mars is actually quite affordable.
For more cool photos of Mars have a look at Amazing Features of Mars.
Sources: http://www.nasa.gov/mission_pages/mars/main/index.html
I think its important to note that the lower gravity of the smaller planet is not the main reason why mars has less atmosphere. It's more so believed to be because of the lack of a molten core, therefore a lack of a magnetic field to protect Mars from the sun's CMEs (coronal mass ejections). Earth and Venus (and the gas giants) have this field which protects the atmosphere from being stripped away. This is also the cause of the auroras. Mars is thought to have had an atmosphere at one time, which is what would have allowed a water cycle to exist which is shown in many land features of mars. There are many theories as to why Mars no longer has a molten core and most revolve around valles marineris, olympus mons, and the tharsis region or some sort of large asteroid collision that cracked the Martian crust.
ReplyDeleteYes that also has a significant impact on atmosphere retention as well but only to a certain extent. The "solar winds" also strip off a fair portion of atmosphere. Yet it has been a rather long time since Mars had a magnetosphere and still there is an atmosphere. The much lower gravity just simply can't hang onto a huge a atmosphere. and with the effects of solar wind stripping has resulted in what we see today. I would say that the strength of solar winds and gravity have now equalised and the gravity is strong enough to hold onto the atmosphere regardless of the solar winds.
DeleteLike many, Mars has always fascinated me. I very much enjoyed learning more about it with what you had to share. It was a fun read for me. :-)
ReplyDeleteThanks Susan, I am glad to hear that.
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