Seasonal and Daily Changes on Mars Global and local dust storms; Dust devils; Eroded rock and dunes;...
-
date post
21-Dec-2015 -
Category
Documents
-
view
217 -
download
2
Transcript of Seasonal and Daily Changes on Mars Global and local dust storms; Dust devils; Eroded rock and dunes;...
Seasonal and Daily Changes on Mars
• Global and local dust storms;
• Dust devils;
• Eroded rock and dunes;
• Polar Caps and their variation by season;
• Layers within caps;
• Other cold-climate features;
• Cause of climate changes on Mars?
The material eroded from rocks forms many dunes.Show constant wind direction for long periods of time.
Winter Spring Summer
Changing shape of the South Polar Cap due to seasons
Frost
Cap
MOLA data indicate that this eroding layer is about 10 cm thick
The obliquity of Mars may have varied from almost 0 – 60 degrees
So how do we get these longer seasonal changes
on Mars?
The precession may have changed climate
dramatically in the past on timescales of 25,000 –
175,000 years
Viking Biology Experiments
1. Labeled release experiment, looked for signs of metabolism
2. Pyrolytic release experiment, looked for signs of photosynthesis
3. Gas exchange experiment, looked for signs of respiration
In 1996, possible “fossils” were found in a meteorite from Mars!
ALH 84001 originated as a slowly-cooled igneous rock in the Martian crust, was excavated by an impact, altered by fluids, and finally sent to Earth by another impact. The consensus among most researchers is that these are not fossils but”ludae naturae” (playthings of nature), of inorganic origin.