[X] My Assistant

[SigurRosFan]

http://www.esa.int/SPECIALS/Mars_Express/SEMIPVMVGJE_0.html - Eastern scarp of Olympus Mons (Press Information)

http://www.esa.int/SPECIALS/Mars_Express/SEMIPVMVGJE_1.html - Eastern scarp of Olympus Mons (Images)

Image was taken on Nov. 23, 2004:


Lava flows are up to 200 million years old and the network-bearing area was geologically active as recent as 30 million years ago.

[edstrick]

"....I can't remember actually noticing *any* cloud shadows on Mars before these - lots of clouds, but no shadows..."

Viking Orbiters repeatly saw an unusual cirrus-like cloud in the southern mid-lattitudes somwhere southwest or southeast of the Gusev landign site, maybe about 45 or so south. It was crisply defined, at exceptionally high altitude, and often cast well defined discrete shadows. (altitude directly measured from shadows... 15 or 25 or something km!) The general expectation was that these were recurring CO2 "cirrus" forming where uplift of mid-latitude jetstream or something similar tended to push the temperature below condensation point.

------------------

"Edstrick, I cannot figure out that 3 Tharsis volcans are higher than Olympus and then Olympus is "taller" than Tharis volcanos. Do you refer that the Tharsis volcanos has higher level of surface base than Olympus Mons? "

Olumpus is tallest, base to peak, as Mauna Kea (Is that the peak on Hawaii?) is the tallest mountain on Earth. MOLA data showed, I'm pretty sure, that one of the Tharsis trio has the highest altitude relative to the martian geoid ("sea" level datum: gravitational equi-potential surface) on Mars. Don't expect the PR geniuses at NASA to get their educational materials up to date and accurate, if only because they aren't the experts on all sorts of gobs of data published in (to them and many of us) obscure locations. Check peer-reviewed primary mission reports in places like Journal of Geophysical Research for the MOLA data.