Monday, December 14, 2009

Whipple Lecture: JP Bibring

Too much in Dr. Bibring's lecture for a proper tweet, here's a summary.

Mars can teach us "Why Earth is unique and what drives its evolution"

Results from OMEGA Near IR imaging.

1. Mars clouds and climate change.
Most clouds water vapor
Localized mesospheric (80 km) CO2 clouds, maybe nucleated from magnetite.
(my comment: if so, can solar wind directly help in the lofting of these particles?)

2. Mars a dead planet?
Appears to be no more outgassing is what is thought.
In North polar region dark gypsum dunes around H2O on caps, could be last places with venting.

3. Where is the Co2. Ice? Carbonate?
South Pole has CO2, but mostly H20.
No significant carbonate (which would be made by liquid water).
N2 and CO2 lost (probably) by atmospheric escape, not in ice or carbonate

4. Altered materials?
Rust layer VERY thin, NOT in cratered regions. Not due to liquids. Due to slow atmospheric over millions of years with H2O2.

"red --> rust --> water --> life --> NO"

Hydrated phyllosilicates (not clays) could be association with life.

Consider this figure. If picture of ehb/lhb (e.g. secondary peak) is correct liquid water may (and habitability) may have occurred between the 2 (on Earth as well). On Mars the dynamo shut off during lhb, and with no field to hold off energetic solar particles dense atmosphere/water lost after this. Mars data consistent with this, volcanism occurred after this time and not associated with liquid water and no magnetism (cause Mars not massive enough, insufficient mantle convection). So "poster" picture you see sometimes of a Mars with active volcanos AND oceans is wrong.

5. Phobos and Deimos are more likely parts of Mars after impact like the Moon. Not captured asteroids.

I'm probably not doing this justice but it was a interesting, thought provoking talk, I enjoyed it. Notion of Earth having ocean/life between the ehb and lhb has legs as far as I'm concerned, as pointed out we say life started after but we have no Earth left accessible to us to tell if indeed life was there before. Bibring claims only 10-15% of ocean would evaporate during lhb on Earth.

My battery (laptop and body) needs recharging, I'm out of here.

ps: "geo-pigeon", the renegade pigeon who appeared during the talk and has visited the Donor lounge twice whilst I type this appears to be gone for now.


  1. You lost me at OMEGA.
    swimbikerun, please.

  2. Sorry La, but I’m a “cub reporter” at the American Geophysical Union Meeting and am sharing some notes with folks on a lecture we had this afternoon about what Mars can teach us about Earth’s evolution.