June 27, 2008

Mission Finds Nutrients in Soil That Could Support Life


By John Johnson Jr.

Los Angeles Times

The first chemistry results from Mars' northern plain reveal an environment more hospitable to life than some scientists had predicted, one that might allow future colonists to grow crops as familiar on Earth as asparagus and green beans.

Strawberries, though, might be tougher, Phoenix mission scientists said Thursday.

"We're flabbergasted by this data," said Sam Kounaves, the lead scientist on the wet chemistry experiment for the Phoenix spacecraft, which landed on Mars on May 25. "We've found nutrients that could support life."

A sample of soil about the size of a sugar cube was delivered to the lab by the lander's nearly 8-foot-long robotic arm and mixed with water brought from Earth. Analysis shows that the soil is alkaline, with a pH between 8 and 9, Kounaves said. This came as a surprise, at least to the many scientists who have argued that Martian soil was likely too acidic to support life.

With that level of alkalinity, "you might be able to grow asparagus very well," Kounaves said. Strawberries, on the other hand, require more acidic soils. The test also turned up magnesium, sodium, potassium and chloride, all of which are useful in organic processes.

The test did not turn up the prize that the $420 million mission was sent to find: complex organics that would indicate Mars once was, or still might be, habitable. Organic compounds, made up of carbon in combination with nitrogen, hydrogen and other elements, are necessary to build the chemical scaffolding of life as we know it on Earth.

Further, even though the soil chemistry would provide some nutrients for life, any future crops would have to be grown underground, because the meager Martian atmosphere lets in too much of the sun's destructive ultraviolet rays.

The Martian soil looks very similar to soils on Earth, only without organics, Kounaves said.

The scientific team from the University of Arizona and the Jet Propulsion Laboratory in La Canada Flintridge, Calif., emphasized that these results represent an analysis of a single piece of a Martian landscape that is the size of the Earth's land area.

Originally published by BY JOHN JOHNSON JR..

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