clouds on Mars?

Downloaded this from the ESA site...

Just wondered why, if Mars has no atmosphere, we are told that we are seeing clouds? Also noice the bright object on the left casting a long shadow! The site acknowleges it but gives no explanation as to what it actually is...

Sorry to burst your bubble mate, but Mars has an atmosphere, clouds and storms.

if it was the moon then it'd be a different story

reply to post by Chadwickus


of course it has atmosphere,and of course it has clouds...
it's all visible on numerous nasa Mars strips

but don't these clouds suggest an active water biosphere circulum?

reply to post by darkraver



If you mean there must be liquid water the answer is no. Water ice can turn directly to water vapor without passing through the liquid phase. The process is called sublimation.

For water, wouldn't a reasonable amount of energy (heat) be required to initiate sublimation.

reply to post by BreakOut

Sublimation occurs more readily when certain weather conditions are present, such as low relative humidity and dry winds. Sublimation also occurs more at higher altitudes, where the air pressure is less than at lower altitudes. Energy, such as strong sunlight, is also needed. If I was to pick one place on Earth where sublimation happens a lot, I might choose the south face of Mt. Everest. Low temperatures, strong winds, intense sunlight, very low air pressure—just the recipe for sublimation to occur.

ga.water.usgs.gov...

Sounds like Mars is the perfect place.

Originally posted by clanky2008
Just wondered why, if Mars has no atmosphere, we are told that we are seeing clouds?

You should brush up your knowledge about Mars.

As far as I remember Mars was never considered as a planet without atmosphere, and the dust storms are one of the most famous features of Mars.

Here you can see a small animation made with some photos taken by one of the Mars rovers, Opportunity.

Edited to remove the asking of a link, I found the image here,

[edit on 23/8/2008 by ArMaP]

reply to post by darkraver


There is no need of a biosphere to have clouds.

Two interesting articles about it can be read on ESA's site, The origin of perennial water-ice at the South Pole of Mars talks about how the ice on the south pole got there and why the south pole has more ice than the north pole, and Ice clouds put Mars in the shade talks about the other clouds, the CO2 clouds.