The story I’m about to tell is a work of fiction, but it could very well happen in reality one day. If it did, it could cause an enormous scandal in the scientific community, ruin what remains of NASA’s reputation, and end the careers of anyone directly involved.
The year is 2020. NASA’s latest Mars rover, Intrepid, has landed successfully and wheeled around a bit, proving that all its systems are functioning. Intrepid’s predecessor, the Curiosity rover, found evidence in 2013 that life could exist on Mars, but Curiosity wasn’t equipped to test if any life forms do exist there. Intrepid’s mission is to follow up on Curiosity’s work.
NASA engineers have equipped Intrepid with state-of-the-art biochemical research equipment. They gave it new technology that wasn’t available when Curiosity was launched, as well as delicate, new digging tools for collecting soil samples. Scientist carefully selected Intrepid’s landing site, putting it near what they believe is subsurface liquid water melting from one of Mars’s polar ice caps.
Intrepid begins its work, and the very first test comes back positive. There’s bacterial life on Mars! Scientists around the world celebrate. The media goes crazy, and the old theory that life on Earth began on Mars is revived once again when someone notices similarities between the DNA of the Martian microbes and that of life on Earth. In fact, the Martian bacteria seem to have a lot in common with E. coli.
But the next test shows fewer bacteria. The one after that shows fewer still, and soon no bacteria can be found at all. It seems the “Martian” bacteria aren’t capable of surviving on Mars. Soon, the truth comes out. One of those delicate digging tools was opened before it left, meaning it may have been contaminated. Previous studies have already shown that E. coli might be able to survive in space if shielded from ultraviolet radiation.
End of story.
Currently, the United States is part of an international agreement called the Outer Space Treaty, which stipulates that any probe we send to another planet must be thoroughly decontaminated. NASA even has a Planetary Protection Officer, Dr. Catherine Conley, in charge of making sure that we don’t introduce invasive species to alien worlds. The point of all this is not only to protect alien ecosystems (if they exist) but to ensure that if we do discover life on another planet, we’ll know for certain that its genuine alien life and not something that stowed away on our own space vehicles.
And yet despite the Outer Space Treaty, despite NASA’s own rules and Dr. Conley’s best efforts, one of Curiosity’s digging apparatuses was opened and potentially contaminated before it left Earth in 2011. Could any bacteria have survived the long journey to Mars? We don’t know. It’s possible. So far it doesn’t seem like any harm was done, but this could be a costly mistake if it ever happens again.