Images Suggest Water May Flow Seasonally on Mars

Dark features on the side of Martian mountains might be evidence of salty liquid water that flows in warmer months. (NASA)

The University of Arizona operates a high-powered camera which has detected what may be water flowing seasonally on Mars. The finding was published Friday in Science journal, and is the first of its kind.

The discovery follows detections over the past 15 years of water on Mars in the form of ice and evidence of past water flows in ancient gullies. The presence of ice, and especially flowing water, could mean Mars is, or was at some time, favorable to life.

The latest images were captured from y o2007 through 2011 in the southern hemisphere, and show dark, fingerlike markings that streak the sides of steep slopes. Researchers say that the markings could be evidence of salty water that appears in late spring, disappears during winter and reappears when the weather warms. Additional research is needed to prove the water theory, said the paper's lead author, Alfred McEwen. He added:

"We have this circumstantial evidence for water flowing on Mars. We have no direct detection of water."

The camera is aboard NASA's Mars Reconnaissance Orbiter, which has been circling the planet since 2006.

One of the challenges that Mars poses is that the planet is so large that it has been hard to collect enough images frequently to detect any changes.

Researchers at a NASA press conference on Thursday said that if life exists on Mars, it likely would have adapted to the climate. If water flows seasonally on Mars like the new images suggest, organisms would go into a dormant or resting state. If the cold, salty water never freezes, organisms could remain active but would have a lower metabolic rate.