Space Topics: Mars
The Year in Pictures: 2005
Mars Express Spies an Hourglass Frozen in Time
Credit: ESA / DLR / FU Berlin (G. Neukum) |
March. Throughout the past year, three active orbiters at Mars have
returned evidence of recent geologic activity across Mars. This view
was captured by Mars
Express and shows a fossilized, rubble-covered glacier that once flowed
down the steep valley at right into a small crater, filling it nearly to the
rim. The
glacier overtopped the western edge of the small crater and it continued to
spill downhill into a larger crater, forming an hourglass shape. The
flow of the glacier would have occurred in slow motion over thousands of years. Analysis
of the surface of the glacier has led scientists to conclude that it was last
in motion only a few million years ago, a tiny fraction of the age of Mars. There
may still be significant ice deposits buried beneath the visible surface, protected
from the Martian environment by an insulating lag of rocks and dust.
|
[ what is this? ]