Could the Mars Phoenix lander have been contaminated by bacteria from Earth?
The possibility was raised by rumor-multipliers feasting on an Aviation Week report that the White House had been briefed on “major new Phoenix lander discoveries concerning the ‘potential for life’ on Mars.”
The report has since been retracted, but it raised the prospect, if only wildly, that the Phoenix found Martian soil so habitable because transplanted microbes flourished there. But that, say researchers, is highly unlikely.
Mars explorers have a profound self-interest in ensuring that bacterial hitchhikers don’t confound their results: imagine asking for NASA funding after claiming a plucky strain of underarm bacteria as extraterrestrial life. And if Earthly bacteria survives a trip and then flourishes, it could upset an alien ecosystem — the equivalent of finding something rare and priceless by stepping on it.