June 26, 2008

Scientists Find Soil On Mars May Support Life

NASA scientists said Thursday that the soil on Mars appears to have elements favorable to supporting life. The "flabbergasted" scientists are part of the Phoenix Mars Lander mission. They said a preliminary analysis on a soil sample obtained by the spacecraft's 8-foot robotic arm had shown the Martian soil to be much more alkaline than expected.

"We basically have found what appears to be the requirements, the nutrients, to support life whether past present or future," Sam Kounaves, the Phoenix's lead investigator for the wet chemistry laboratory, said during a news conference with journalists.

"It is the type of soil you would probably have in your back yard, you know, alkaline. You might be able to grow asparagus in it really well....It is very exciting for us."

The $420 million Phoenix lander touched down on Mars a month ago to study the habitability of Mars' northern latitudes.  It has already identified ice on the planet's surface.  

The 35 cubic feet sample soil was taken from about 1 inch below the planet's surface, and was found to have a pH level of 8 or 9.  A pH level less than 7 means the solution is acidic, while a pH over 7 means it is salty.

"We were all flabbergasted at the data we got back," said Kounaves.

When asked if there were any remaining doubts about life on Mars, Kounaves replied that the results were "very preliminary", and that more analysis was required.

"There is nothing about the soil that would preclude life. In fact, it seems very friendly...there is nothing about it that is toxic," he added.

After its ten-month journey from Earth, the Phoenix landed on Mars' north pole region on May 25. It is the latest NASA mission to determine if water, critical in supporting life, was ever present on the planet and whether life, even in its most primitive form, exists or ever existed there.

Last week the scientists said they had definitive proof that ice was on the planet after eight small pieces were observed melting in a series of images. 

Analysis of soil samples placed in the Phoenix's wet chemistry laboratory during the past 24 hours showed the Martian soil contained trace amounts of magnesium, sodium, potassium and other elements.  It was also much less acidic than many scientists had expected.

One mission scientist "jumped up and down as if he had the winning lottery ticket," upon learning the soil's pH levels, according to mission soil analysis specialist Michael Hecht.

"It is a huge step forward," Hecht said.  

The "wet chemistry" technique involves mixing Martian soil with water from Earth, and was used as a way to determine what microbes might be able to survive and grow in the Martian soil.

Levels of salt were reasonable and the calcium levels appeared to be low, the mission scientists said. But the soil's composition could be different within deeper levels below the surface, they added.

To date, Phoenix has not detected any organic carbon, something considered an essential building block of life. There is general scientific consensus that liquid water, carbon-containing compounds and a stable energy source are all required to support life.


Image Caption: The Robotic Arm on NASA's Phoenix Mars Lander carries a scoop of Martian soil bound for the spacecraft's microscope in handout photo released on June 13, 2008. Courtesy NASA/JPL-Caltech/University of Arizona


On the Net:

NASA Phoenix Mission Page