Tesla Roadster in space
Researchers at the Centre for Planetary Science have found that the Tesla Roadster recently sent into space as part of SpaceX's test flight will eventually collide with Earth (or Venus).
Wednesday, February 14 - 2018
Don Campbell

The Tesla Roadster that was recently shot into space as part of SpaceX’s rocket test flight will likely collide with Earth or Venus eventually, finds new U of T Scarborough research. 

“It will likely end up colliding with Earth or Venus, but there’s no need to panic since the probability of that happening even within the next million years is very small,” says Professor Hanno Rein, director of the Centre for Planetary Science and author of the research.  

The car was sent into space as part of the payload for SpaceX’s Falcon Heavy test flight on Feb. 6. While rocket test flights usually have a dummy payload, SpaceX founder Elon Musk sent up his personal Tesla Roadster instead.

Though it’s mostly a publicity stunt – the car doesn’t have any scientific instruments on board – it’s now classified as a near-earth-object, meaning it’s catalogued and being tracked by NASA’s Jet Propulsion Laboratory along with other objects that will travel relatively close to Earth.

What motivated Rein and his team was the question of what will be the car’s long-term fate as it orbits the Earth. After running a series of simulations using sophisticated software that can track the motion of objects in space, they determined the probability of it colliding with Earth and Venus over the next one million years to be six per cent and 2.5 per cent respectively.

They also determined that the first close encounter the Tesla will have with us will be in 2091, when it will pass within a few hundred thousand kilometres of Earth.

The car is currently on a Mars and Earth crossing orbit, meaning it will travel on an elliptical path that repeatedly carries it beyond Mars and then back to Earth’s orbital distance from the sun. How this orbit evolves over time will depend a lot on its encounters with Earth, especially how close it will get to Earth since any small change in its trajectory could have a large effect on its orbit.

While the path of the Tesla can be accurately predicted in terms of years, after hundreds of years and many close encounters with Earth it becomes impossible to predict the object’s precise orbit. By studying a large number of orbital simulations however, the researchers were able to arrive at a statistical distribution of possible outcomes.

Hanno Rein and Daniel Tamayo
Professor Hanno Rein (left) and postdoctoral fellow Dan Tamayo from the Centre for Planetary Sciences wanted to see what the long-term fate of the Tesla Roadster would be after it was launched into space. (Photo by Ken Jones)

“Each time it passes Earth the car will get a gravitational kick,” says Dan Tamayo, a postdoctoral fellow at U of T Scarborough who was a co-author on the paper.

“Depending on the details of these encounters the Tesla can be kicked onto a wider or smaller orbit, so it’s random. Over time the orbit will undergo what’s called a random walk, similar to the fluctuations we see in the stock market, that will allow it to wander the inner solar system.”

While they only ran simulations for the first three million years of its space journey, Rein says the most likely outcome for the Tesla is for it to crash into Earth or Venus in the next 10 million years or so.

“Although we are not able to tell on which planet the car will ultimately end up, we’re comfortable saying it won’t survive in space for more than a few tens of millions of years,” he says.

While the car’s likely final destination is Earth, they note there’s nothing to fear since much or all of it will likely burn up in the atmosphere.

The research, which received funding from the Natural Sciences and Engineering Research Council of Canada (NSERC), will be submitted to the journal Monthly Notices of the Royal Astronomical Society. A preprint of the paper is available online.