The image above shows three Martian lakes. They are just that! Frozen lakes near the south polar region. However they are not quite like lakes onEarth. Though there may indeed be water ice in these lakes like there is under the polar ice cap, the top layer is CO2 ice. The presence of the blackish material could indicate some type of lifeform similar to lichens on Earth. The fact thatthe black areas have been spoted in several regions on Mars and change with the seasons is further indication of possible life. Lichens from Earth would actually make a great transplant to the Martian environment as they require little water, can stand extremes of temperature, and consume CO2 like most plants. They do however give off a large volume of oxygen for such small plants, which makes them excellent candidates for early terraforming needs.

Excerpt:
WASHINGTON (Reuters) March 16, 2007

A spacecraft orbiting Mars has scanned huge deposits of water ice at its south pole so plentiful they would blanket the planet in 36 feet of water if they were liquid, scientists said Thursday.

The scientists used a joint NASA-Italian Space Agency radar instrument on the European Space Agency Mars Express spacecraft to gauge the thickness and volume of ice deposits at the Martian south pole covering an area larger than Texas.

The deposits, up to 2.3 miles thick, are under a polar cap of white frozen carbon dioxide and water, and appear to be composed of at least 90 percent frozen water, with dust mixed in, according to findings published in the journal Science.

Scientists have known that water exists in frozen form at the Martian poles, but this research produced the most accurate measurements of just how much there is.

SOURCE: CNN News

Below is a clip from the Polar Ice cap at the nouth pole showing the same bright white CO2 ice.
 

South Polar Cap in Summer Time...

North Polar Cap and Clouds...
 

Recent Martian Ice Age...

August 2, 2005

Life on Mars? Who knows? Ice on Mars? Most definitely—and now we've got more cold, hard evidence.

On Thursday the European Space Agency released a rare photo of a Martian ice lake in the far northern reaches of the planet. Capping a swirl of dunes at the bottom of a 23-mile-wide (35-kilometer-wide) crater, the frozen lake is thought to exist year-round. The modest temperature and pressure changes in this latitude would not be enough to allow the ice to melt or evaporate.

Water, a key ingredient for life, is believed to have once flowed on Mars, etching the gorges that crisscross the red planet. Today water ice is abundant underground, cakes the poles, and may even form frozen, buried seas (see photo). But it is unusual to find lonely patches of ice away from the poles.

The new image, taken by the agency's Mars Express probe, shows largely true colors. But the depth of the crater's ice-fringed, 1.2-mile-deep (2-kilometer-deep) ridges is exaggerated by a factor of three.

—Ted Chamberlain 

SOURCE: National Geographic