Is That Water on Mars? Mars Express Photo Shows Lagoon Like Feature

European Space Agency's Mars Express orbiter has turned up images that appeared to show water on the Red Planet. Closer scrutiny reveals an optical illusion.

Releasing the image which was taken last November, the agency said that the dark coloring of the surface within craters can be attributed to volcanic, basalt-rich deposits that have built up over time. High velocity winds on the planet erode and sculpt the surface as on Earth and deposit material. ESA's image shows a lagoon like structure in a crater.

"The largest crater in this image also has the steepest rim. With a diameter of some 70 km, this crater dominates the left, southern, side of the frame. At first glance, this image seems to show something amazing in this crater, and in one of its neighbors to the right: is this a hint of blue liquid water? No, it is an optical illusion caused by the image processing. The blue-hued patches lying within the ragged craters are actually dark sediments that have built up over time. Again, this is due to the winds, which carry dark, volcanic, basalt-rich deposits across the planet," the agency said.

ESA also explained the unusual pattern of crater rim erosions. Winds which can hit up to 62 miles per hour often erode crater rims and other surface features over millions of years. .