Explanation:
Fresh evidence of an ancient stream has been found on Mars.
The robotic rover
Curiosity
has run across unusual surface features that carry a strong resemblance to stream banks on Earth.
Visible in the
above image,
for example, is a small overhanging rock ledge that was quite possibly created by water erosion beneath.
The texture of the ledge appears to be a
sedimentary conglomerate,
the dried remains of many smaller rocks stuck together.
Beneath the ledge are numerous small pebbles, possibly made smooth by tumbling in and around the once-flowing
stream.
Pebbles in the streambed likely fell there as the bank
eroded.
Circled at the upper right is a larger rock possibly also made smooth by
stream erosion.
Curiosity has now discovered several indications of
dried streambeds on Mars
on
its way to its
present location where it
will be exploring the
unusual conjunction
of three different types of landscape.
