Washington – Two NASA space probes that visited Mars 30 years ago may have stumbled upon alien microbes on the Red Planet and inadvertently killed them, a scientist theorizes in a paper released Sunday.
The problem was that the Viking space probes of 1976-77 were looking for the wrong kind of life and didn’t recognize it, the researcher said in a paper presented at a meeting of the American Astronomical Society in Seattle.
The new report, based on a more expansive view of where life can take root, may have NASA looking for a different type of martian life form when its next Mars craft is launched this year, one of the space agency’s top scientists told The Associated Press.
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 ’70s, 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 Dirk Schulze-Makuch, author of the new research.
That’s because a water/hydrogen-peroxide mix stays liquid at very low temperatures (minus 68 degrees Fahrenheit), doesn’t destroy cells when it freezes and can suck scarce water vapor out of the air.
The Viking experiments of the ’70s wouldn’t have noticed alien hydrogen-peroxide-based life and, in fact, would have killed it by drowning and overheating the microbes, said Schulze-Makuch, a geology professor at Washington State University.
One Viking experiment seeking life on Mars poured water on soil. That would have essentially drowned hydrogen-peroxide-based life, Schulze-Makuch said. Another experiment heated the soil to see if something would happen, but that would have baked martian microbes, he said.
“The problem was that they didn’t have any clue about the environment on Mars at that time,” Schulze-Makuch said.
The Viking landers were designed and built in Colorado by Martin Marietta Aerospace, now Lockheed Martin.
Schulze-Makuch acknowledges he can’t prove that martian microbes exist, but given the martian environment and how evolution works, “it makes sense.”
In recent years, scientists have found life on Earth in conditions once thought too harsh, such as an ultra-acidic river in Spain and ice-covered lakes in Antarctica.
Schulze-Makuch’s research coincides with work being completed by a National Research Council panel that worries that scientists may be too Earth-centric when looking for extraterrestrial life. The problem for scientists is that “you only find what you’re looking for,” said Penn State University geosciences professor Kath erine Freeman, a reviewer of the NRC work.
