This new image from the European Space Agency's Mars Express orbiter shows
a system of channels on the red planet called the Louros Valles, named in 1982
after river in Greece. They are at the bottom of the picture. North is up.
The Louros Valles complex is south of the Ius Chasma canyon, the dark channel
that runs east to west. The whole setup is part of the giant Valles Marineris
canyon system on Mars.
The Geryon Montes, visible near the top of this image, is a mountain range
that actually divides the Ius Chasma into two parallel trenches (a portion of
the northernmost trench is just visible). The dark deposits at the bottom of
the Ius Chasma are possibly related to water and wind erosion, scientists said.
Scientists do not know if water has flowed recently on Mars, but this picture
hints at past activity.
The Louros Valles complex shows signs of "sapping," erosion by water that emerges
from the ground as a spring or that seeps from between layers of rock in a wall
of a cliff, crater or other type of depression, according to mission scientists.
The channel forms from water and debris running down the slope from the seepage
area.
This is known from similar features on Earth, but on Mars it is thought that
most of the water had probably either evaporated or frozen by the time it reached
the bottom of the slope.
Credit: ESA/Mars Express
