Explanation:
What caused this unusual white 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 that this is not correct.
The light material appears to have
eroded
away from the surrounding area,
indicating a very low-density composition, possibly consistent with volcanic
ash or windblown dust.
The stark contrast between the rocks and the surrounding
sand is compounded by the sand's
unusual darkness.
This picture
was taken from the Mars Expressspacecraft currently orbiting
Mars.
Planetary scientist Emily Lakdawalla, among others, has followed her curiosity about this unusual Martian landform into a
fascinatinginvestigation
that is eloquently described in the
Planetary Society Weblog.
The mysterious
white rock spans about 15 kilometers across inside a
larger crater that spans about 100 kilometers.
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