A red Tesla convertible hitched a ride to space with a SpaceX rocket in early February, bringing with it what may be the largest load of earthly bacteria to ever enter space. 
 
 NASA's Office of Planetary Protection makes sure spacecraft planning to land on other planets are sterile. Much like an invasive species, organisms from Earth could thrive on another planet and wipe out native organisms. After all, it was bacteria that stopped the Martian invasion in H. G. Wells' fictional "War of the Worlds." 
 
 "If there is an indigenous Mars biota, it's at risk of being contaminated by terrestrial life," said Jay Melosh, a professor of earth, atmospheric and planetary sciences at Purdue University. "Would Earth's organisms be better adapted, take over Mars and contaminate it so we don't know what indigenous Mars was like, or would they be not as well adapted as the Martian organisms? We don't know." 
 
 But the Office of Planetary Protection doesn't regulate spacecraft that plan to stay in orbit; since the Tesla was never intended to land, it wasn't cleaned before takeoff. 
 
 "Even if they radiated the outside, the engine would be dirty," Melosh said. "Cars aren't assembled clean. And even then, there's a big difference between clean and sterile." 
 
 The Tesla could potentially land on Mars, although it's unlikely, he said. The car is in an orbit that crosses Earth's and Mars', and it will probably end up striking Earth, but it could be millions of years before that happens. 
 
 Extreme temperatures, low pressure and unfiltered cosmic radiation make space an inhospitable environment for living organisms. It doesn't always kill them, though – some bacteria go dormant in the vacuum of space and wake up again when conditions are right. 
 
 Alina Alexeenko, a professor of aeronautics and astronautics at Purdue, works in a lab that specializes in freeze-drying bacteria and biologics. The freeze-drying technology is used for long-term preservation of live virus vaccines, bacteria and biopharmaceuticals – a process similar to what live organisms experience in space. 
 
 "The load of bacteria on the Tesla could be considered a biothreat, or a backup copy of life on Earth," she said. 
 
 Explore further: Tesla shot into space will likely collide with Earth or Venus—in millions of years: researchers ||||| SpaceX's launch of a Tesla Roadster into deep space may have got 10 out of 10 for style and PR, but it looks as if it got one out of 10 for cleanliness. According to scientists at Purdue University, the electric sports car and its plastic mannequin driver may be the dirtiest unmanned objects ever launched into orbit – carrying an unprecedented amount of bacteria that could one day contaminate Mars. 
 
 Anyone who's ever bought a second-hand car knows that they're likely to find unpleasant surprises under the seats or tucked in the glove box. In fact, if you were to commission a forensic analysis of the average used vehicle with its collection of skin flakes and dried mucus, you'd probably never get into another one without a hazmat suit on. 
 
 Not surprisingly, spacecraft tend to be a bit more hygienic. International agreements require any unmanned probe that is likely to land on another planet, moon, asteroid, or other celestial body meet rigorous sterilization standards inside and out to minimize the chance of terrestrial microbes ending up colonizing another world. At the minimum, this would complicate the job of scientists seeking alien life, but it could have worse effects. 
 
 "If there is an indigenous Mars biota, it's at risk of being contaminated by terrestrial life," says Jay Melosh, a professor of earth, atmospheric and planetary sciences at Purdue. "Would Earth's organisms be better adapted, take over Mars and contaminate it so we don't know what indigenous Mars was like, or would they be not as well adapted as the Martian organisms? We don't know." 
 
 Legally, this requirement doesn't apply to spacecraft that won't land on other planets, like those that orbit the Earth or the Sun, but space engineering is already a pretty scrubbed enterprise with satellites being assembled in special clean rooms to keep delicate equipment from being contaminated by dust, dirt, and other undesirables. Ultimately, the main difference between a lander and a non-lander is that the former are built to withstand being steamed in a giant autoclave designed to kill off any microscopic hitchhikers. 
 
 By comparison, the Tesla Roadster is extremely dirty. It's an ordinary production car that was driven personally be SpaceX founder Elon Musk on public roads and wasn't specially cleaned before the launch – not that that would have helped much. 
 
 "Even if they radiated the outside, the engine would be dirty," says Melosh. "Cars aren't assembled clean. And even then, there's a big difference between clean and sterile." 
 
 Of course, the Roadster is in a heliocentric orbit that will likely keep it circling the Sun for tens of millions of years until the gravitational influence of Earth, Mars, and Jupiter disturb it. And it's now much more sterile than it was. Every moment until it eventually burns up in the atmosphere of the Earth or Mars or plunges into the Sun, it's being pelted with micrometeoroids and bombarded by hard ultraviolet and cosmic rays as it bakes in temperatures of up to 260° F (127° C). 
 
 Such conditions will kill any bacteria on the car's surface, and as the plastic body disintegrates under this cosmic onslaught, there will be fewer places to hide. However, some places inside the frame and drivetrain will still provide tiny protective havens where microbes can freeze dry and go dormant for thousands or perhaps millions of years. 
 
 The fear is that there is a remote chance that fragments of the Roadster might land on Mars in the distant future, though it's more likely to burn up completely in the thin Martian atmosphere. But Alina Alexeenko, a professor of aeronautics and astronautics at Purdue sees this as a glass half empty/half full situation.
– In the small chance that Elon Musk's space-exploring Tesla Roadster comes crashing back to Earth, experts say the planet will be just fine. It's a different story with Mars, where the car could become what one scientist calls a "biothreat." The Tesla, in a large orbit around the sun, is unlikely to get too close to Mars in the distant future, and if it does, it'll likely burn up in Mars' atmosphere. But Purdue University scientists say that even traces of the vehicle could contaminate or wipe out indigenous life on the Red Planet, should it exist. That's because, unlike spacecraft intended to land on celestial bodies, the Tesla did not undergo careful sterilization overseen by NASA's Office of Planetary Protection. With New Atlas pointing out the car was driven on public roads, scientists are calling it "the largest load of earthly bacteria to ever enter space." "Even if they radiated the outside, the engine would be dirty," researcher Jay Melosh says in a release. "Cars aren't assembled clean. And even then, there's a big difference between clean and sterile." Life in space, with its extreme temperatures, low pressure, and cosmic radiation, will help kill some earthly bacteria. But some could lay dormant for millennia. Noting her office had little involvement in the launch of the Tesla, Planetary Protection Officer Lisa Pratt tells Space News that future commercial space missions will present similar problems, as it's "virtually impossible for a commercial mission to meet" current sterilization requirements for spacecraft. "We have to figure out how to work closely, how to move forward in a collaborative posture so we don't have another red Roadster up there in orbit." (Scientists are also annoyed by a fake star.)