Viking killed Martian life in the '70's... Jan 7, 2007 21:13:26 GMT -6
Post by Chicago Astronomer Joe on Jan 7, 2007 21:13:26 GMT -6
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.
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.