When Elon Musk launched his Roadster on the inaugural flight of the Falcon Heavy, it was (mostly) a fun PR stunt wrapped around a genuinely impressive event. The mission wasn’t entirely unscientific — the “Starman” at the wheel of the roadster was dressed in SpaceX’s commercial space suit and monitors were attached to detect radiation levels — but it was mostly a fun alternative to launching, say, a giant block of concrete. Now scientists think they can rule out Mars as a long-term likely final resting place for Musk’s machine.
That’s particularly important, given what we know about Mars. The Roadster wasn’t sterilized prior to its launch. And we know that extremophile bacteria on Earth can survive in conditions similar to that on Mars, including anaerobic bacteria that produce methane, a gas we’ve detected in Mars’ atmosphere and have yet to completely explain. This does not mean the methane is automatically produced by organic life (there are inorganic processes that can achieve the same effect), but that uncertainty is why some scientists were concerned. The last thing we would want to do is introduce Earth organisms into the Martian environment where they might kill the very organic life forms we’d like to find, before we’ve ever found them.
Three researchers at the University of Toronto have modeled the likely orbits of the Roadster. First, here’s the vehicle’s current position and orbit, courtesy of WhereIsRoadster. The site cheekily notes the Roadster has already blown through its 36,000 mile warranty 485.5 times (as of this writing).
See how closely the Roadster’s orbit is expected to track our own? That’s expected — it’s the result of the Roadster having launched from Earth. But it’s also the reason why Mars isn’t seen as a likely destination for the vehicle. As the Roadster orbits over time, the Earth will continue to tug on its position when the two pass near one another.
This interplay makes it harder to tell what the Roadster’s orbit will look like in the long term; it could be flung out of the near solar system and out into the Kuiper Belt, for example. But based on the most likely conditions, the Toronto researchers found a 6 percent chance that the Roadster ends up back on Earth, and a 2.5 percent chance that it impacts Venus. The atmosphere on Venus is so dense at ground level, meteors below a certain size don’t hit the ground hard enough to make impact craters. And volcanoes of the sort found on Earth are unknown, due to the incredible pressure that actually prevents a lava fountain. The chances of life existing on the surface, at its balmy 800C, are basically nil.
The researchers believe the Tesla Roadster’s lifespan in our solar system can be measured in tens of millions of years, not hundreds of millions, even in the longest time frames. While it’s possible that the car could still wind up impacting another planet, no evidence to suggest this was found within the 3.5 million-year window they examined. Hopefully we’ll have checked Mars for signs of life long before then. The GIF above, taken earlier this month, shows the Roadster in space as visible through a telescope. In the weeks ahead, it’ll take far more powerful telescopes to keep the car in view. But we got to see it with relatively simple equipment for several days after the launch.