Explanation:
What caused this unusual light rock formation on Mars?
Intrigued by the possibility that they could be salt deposits left over as an ancient
lakebed dried-up,
detailed studies of these fingers now
indicate a more mundane possibility: volcanic ash.
Studying the
exact color of the formation indicated the possible
volcanic origin.
The light material
appears to have
eroded away from surrounding area,
indicating a very low-density substance.
The stark contrast between the rocks and the surrounding
sand is compounded by the
unusual darkness of the sand.
The above picture was taken with the
Thermal Emission Imaging System on the
Mars Odysseyspacecraft currently orbiting
Mars.
The image spans about 10 kilometers inside a
larger crater.
