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[Chicago Astronomer - Astro Joe]

Scientist: NASA found life on Mars - and killed it

WASHINGTON (AP) -- Two NASA space probes that visited Mars 30 years ago may have found alien microbes on the Red Planet and inadvertently killed them, a scientist is theorizing.

The Viking space probes of 1976-77 were looking for the wrong kind of life, so they didn't recognize it, a geology professor at Washington State University said.

Dirk Schulze-Makuch presented his theory in a paper delivered at a meeting of the American Astronomical Society in Seattle, Washington.

Last month, scientists excitedly reported that new photographs of Mars showed geologic changes that suggest water occasionally flows there -- the most tantalizing sign that Mars is hospitable to life.

In the 1970s, the Viking mission found no signs of life.

But it was looking for Earth-like life, in which salt water is the internal liquid of living cells.

Given the cold dry conditions of Mars, life could have evolved on Mars with the key internal fluid consisting of a mix of water and hydrogen peroxide, said Schulze-Makuch.

That's because a water-hydrogen peroxide mix stays liquid at very low temperatures, or -68 degrees Fahrenheit, and doesn't destroy cells when it freezes. It can suck water vapor out of the air.

The Viking experiments of the 1970s wouldn't have noticed hydrogen peroxide-based life and, in fact, would have killed it by drowning and overheating the microbes, said Schulze-Makuch.

One Viking experiment seeking life on Mars poured water on soil. That would have essentially drowned hydrogen peroxide-based life, he said. And different experiment heated the soil to see if something would happen which would have baked Martian microbes.

"The problem was that they didn't have any clue about the environment on Mars at that time," Schulze-Makuch said. "This kind of adaptation makes sense from a biochemical viewpoint."

Even Earth has something somewhat related. He points to an Earth bug called the bombardier beetle that produces a boiling-hot spray that is 25 percent hydrogen peroxide as a defense weapon.

Schulze-Makuch acknowledges he can't prove that Martian microbes exist, but given the Martian environment and how evolution works, "it makes sense."

The paper was released Sunday.

Source:

tinyurl.com/yyoplc

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I agree that in the 1970's, scientists were looking for Earth like organisms, and excluded any thing else that did not reflect what they wanted to find. Many astrobiologists have revisited the data from the Viking missions and concluded that there is room for martian life speculation.

[Chicago Astronomer - Astro Joe]

New Analysis of Viking Mission Results Indicates Presence of Life on Mars

We may already have ‘met’ Martian organisms, according to a paper presented Sunday (Jan. 7) at the meeting of the American Astronomical Society in Seattle.

Dirk Schulze-Makuch of Washington State University and Joop Houtkooper of Justus-Liebig-University, Giessen, Germany, argue that even as new missions to Mars seek evidence that the planet might once have supported life, we already have data showing that life exists there now—data from experiments done by the Viking Mars landers in the late 1970s.

“I think the Viking results have been a little bit neglected in the last 10 years or more,” said Schulze-Makuch. “But actually, we got a lot of data there.” He said recent findings about Earth organisms that live in extreme environments and improvements in our understanding of conditions on Mars give astrobiologists new ways of looking at the 30-year-old data.

The researchers hypothesize that Mars is home to microbe-like organisms that use a mixture of water and hydrogen peroxide as their internal fluid. Such a mixture would provide at least three clear benefits to organisms in the cold, dry Martian environment, said Schulze-Makuch. Its freezing point is as low as -56.5o C (depending on the concentration of H2O2); below that temperature it becomes firm but does not form cell-destroying crystals, as water ice does; and H2O2 is hygroscopic, which means it attracts water vapor from the atmosphere—a valuable trait on a planet where liquid water is rare.

The Phoenix mission to Mars, which is scheduled for launch in August, 2007, offers a good chance to further explore their hypothesis. Although the mission’s experiments were not designed with peroxide -containing organisms in mind, Phoenix will land in a sub-polar area, whose low temperatures and relatively high atmospheric water vapor (from the nearby polar ice caps) should provide better growing conditions for such microbes than the more “tropical” region visited by Viking. Schulze-Makuch said the tests planned for the mission, including the use of two microscopes to examine samples at high magnification, could reveal whether we had the answer all along—and if we’ve already introduced ourselves to our Martian neighbors in a harsher way than we intended.

“If the hypothesis is true, it would mean that we killed the Martian microbes during our first extraterrestrial contact, by drowning—due to ignorance,” said Schulze-Makuch.

Source: www.physorg.com/news87401064.html

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Now that we are better educated, perhaps we can conduct better experiments.