LOS ANGELES "Flabbergasted" NASA scientists said on Thursday that Martian soil appeared to contain the requirements to support life, although more work would be needed to prove it.
Scientists working on the Phoenix Mars Lander mission, which has already found ice on the planet, said preliminary analysis by the lander's instruments on a sample of soil scooped up by the spacecraft's robotic arm had shown it 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 lead investigator for the wet chemistry laboratory on Phoenix, told 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 1 cubic meter (35 cubic feet) of soil was taken from about 1 inch below the surface of Mars and had a pH, or alkaline, level of 8 or 9. "We were all flabbergasted at the data we got back," Kounaves said.
Pressed on whether there was still any doubt that life existed on Mars in some form, Kounaves said the results were "very preliminary" and more analysis was needed.
But he added: "There is nothing about the soil that would preclude life. In fact, it seems very friendly ... there is nothing about it that is toxic."
The $420 million Phoenix lander touched down in the north pole region of Mars on May 25 after a 10-month journey from Earth. It is the latest NASA bid to determine whether water -- a crucial ingredient for life -- ever flowed on the planet and whether life, even in the form of mere microbes, exists or ever existed there.
Scientists said last week they had definitive proof that ice was on the planet after eight dice-sized chunks were seen melting away in a series of photographs.
Analysis in the past 24 hours of soil placed in the spacecraft's wet chemistry laboratory showed it to be less acidic than many scientists expected. It also contained traces of magnesium, sodium, potassium and other elements, they said.
When told the pH levels, one colleague "jumped up and down as if he had the winning lottery ticket," mission soil analysis specialist Michael Hecht told a telephone news conference.
"It is a huge step forward," Hecht said, adding the "wet chemistry" technique, which involves mixing Martian soil with water brought from Earth, was aimed at discovering what native Martian microbes might be able to live, survive and grow in the soil.
The mission scientists said levels of salt were reasonable and the calcium levels appeared to be low but they warned that the composition of the soil could change at deeper levels below the surface.
They also would not be drawn on what form of life the Martian soil might have supported.
(Editing by Peter Cooney)