If your spaceship crashed on Mars, what would survive? Perhaps not you, but the bacteria on your hands might.
Dr. Daniel Austin of the Department of Chemistry and Biochemistry and Brandon Barney, one of his PhD students, are currently experimenting with accelerating charged bacteria to very high speeds and crashing them onto dense targets. So far, the experiments have shown that bacteria can survive these crashes even at speeds of 120 meters per second or almost 270 miles per hour.
These bacteria are so resilient, in fact, that Austin and Barney had a hard time trapping the bacteria long enough to get a measurement because the bacteria were bouncing everywhere.
“We had a lot of trouble with bouncing initially; they were bouncing right out of the container,” Austin said. “Only later did we realize why we weren’t getting any results—they were all bouncing out!”
Now that Austin and Barney can effectively test the speeds at which germs can survive a collision, NASA is interested in applying the research to find out whether bacteria would be able to survive a spacecraft crash and grow on a foreign planet.
“For example,” Austin explained, “Not all spacecraft that have been or are going to Mars are completely sterilized. They still contain viable bacteria that could be released to the Martian surface. Even if the mission is successful, we don’t want to detect signs of life that are a result of things that we brought with us.” Preventing this contamination is what NASA calls “planetary protection.”
Equally important is the question of reverse contamination—that we make sure nothing harmful is brought back to earth on a sample return mission, if microbial life exists on Mars or elsewhere in the solar system.
Austin and Barney will soon submit their findings to the planetary science journal Icarus. In the future, Austin hopes this research will be able to tell other scientists whether potential life found on other planets was original to that planet or whether it was brought from earth.
“They want to be able to say, ‘We see signs of life, and we are confident this is not life we brought with us from Earth, because of how careful we’ve been,’” Austin said. “We want to keep the planets in their natural environment.”