Conditions on Mars were once right for life

Posted by Emma Woollacott

College Station, Texas - Mars is a lot like Earth, from its landscape and soil right down to its snowy weather, data from the Phoenix lander reveals.
 
Mark Lemmon, a professor of atmospheric sciences at Texas A&M University who has been involved with Mars missions for years, says last year's Phoenix Mars Lander mission indicates that Mars could once have supported life.

"To sum it up, we found a place on Mars that is similar to cold, dry environments on Earth, and those environments are capable of supporting life," he said.

NASA's instructions to researchers on the mission were simple: "Follow the water." While no water in a liquid state has been found yet, but there is new evidence that Mars had liquid water billions of years ago.

"Where [Phoenix] landed is a barren place that resembles the dry valleys of Antarctica," said Lemmon. "The area has mounds and troughs, and just like in Antarctic valleys, there is no liquid water but plenty of ice. Some of these patches are fairly pure. Others have the ice mixed with soil containing energy sources and nutrients that could be used if there were life."

Lemmon says the soil has perchlorate, a form of chlorine that is considered hazardous, but certain types of bacteria are able to live on it here. "The interesting thing is, the soil has a potential energy source and oxygen source for life on Mars," he notes.

Traces of calcite were also found, which shows a presence of liquid water at some time in the past, Lemmon notes.

Phoenix also found weather patterns similar to those on Earth, including cold fronts that bring in gusty winds and sub-freezing temperatures. It also saw small Martian snowflakes, leading the team to believe that snowfall on Mars was once a common occurrence.

The report is published in the current issue of Science magazine.

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