Earlier this month, Elon Musk’s SpaceX successfully launched its Falcon Heavy rocket into space. The payload included Musk’s red Tesla Roadster carrying a mannequin the company called Starman. The Tesla is well into space now and is headed towards an orbit that will put it in close proximity to Mars.

At first blush, that might not seem to be a problem. But Purdue professor Jay Melosh said Earth-bound bacteria could wreak havoc on Mars.

“If there is an indigenous Mars biota, it’s at risk of being contaminated by terrestrial life,” Melosh said in a statement. He added that NASA’s Office of Planetary Protection sterilizes spacecraft that will land on other planets to ensure our native bacteria doesn’t interact with the organisms elsewhere. He claimed in his statement that Tesla didn’t sterilize Musk’s car, “bring with it what may be the largest load of earthly bacteria to ever enter space.”

Get Data Sheet, Fortune’s technology newsletter

It’s unclear what exactly that bacteria could do on Mars. But Melosh questioned whether it might “take over Mars and contaminate it.” Purdue pointed to H.G. Wells’ “War of the Worlds,” in which a Martian invasion was thwarted by bacteria.

Still, there’s a chance the concerns might be moot. Space’s extreme conditions could kill most, if not all, of the car’s bacteria. And if it never crashes into Mars, that would limit its exposure on the Red planet.

But what if the bacteria does more than just wipe out bacteria on Mars?

Another Purdue professor, Alina Alexeenko, works in a lab at the university that focuses on preserving bacteria and biologics. She said in a statement that it could cause problems on Mars—but it could also send life on Earth across the universe.

“The load of bacteria on the Tesla could be considered a biothreat, or a backup copy of life on Earth,” she said.

SpaceX did not respond to a Fortune request for comment on the scientists’ claims.