This site is best viewed at 1280x1024
Petri Dish Crater: Mars Civilization Evidence #876
What are we seeing in this crater? All italic text on this page comes from Wikipedia: Life on Mars
Thanks to NASA/ESA/MALIN Space Labs/USGS/ASU for these original images.
"Dark dune spots appear every spring. Dune spots are features that can be seen mainly in the southern polar region (between 60°-80° latitudes) of Mars, on or under the polar ice sheet. The spots were discovered by images obtained by the Mars Global Surveyor in 1998 - 1999. The spots appear at the beginning of the Martian spring and disappear by the beginning of the winter.
...theory of the spots' possible biological origin is made by a Hungarian team; they propose that the spots are colonies of photosynthetic Martian microorganisms.
NASA's current theory is that the patches are composed of either basaltic ash fragments or aggregates of a minor, dark dust component
of the layered deposits that forms as a sublimation residue.
The European Space Agency ( ESA) has not yet formulated a theory, it has stated that the location and shape of the spots is at odds with a physical explanation.
For comparison, here is the image inverted
Below is the full unedited original NASA image.
If these are dethawing dunes, why do they have circular bands around them?
This is a very unusual feature.
Welcome to Mars Ruins