Andrew Masterson
Andrew Masterson is a former editor of Cosmos.
It would be – at least from this distance in time – perhaps the most sublime slapstick event ever.
Imagine: the year is 2091. A man walks through a glorious, sunlit meadow. Cows low gently in the distance. Birds hoot and trill. Trees whisper and sway. All is peaceful and bucolic.
Suddenly, from high in the sky, an 83-year-old cherry red Tesla Roadster comes zooming downwards through the wispy clouds and lands with an almighty smash. When the cloud of dust and clods clear, our man has gone, and in his place lies the fractured remains of a vintage shop mannequin clad in a tattered astronaut suit.
Of course, this almost certainly won’t happen – but the possibility that it will nevertheless exists, according to research conducted by a team led by astrophysicist Hanno Rein from the University of Toronto in Canada.
Like much of the developed world, Rein and his colleagues watched with interest the televised launch of SpaceX’s Falcon Heavy rocket on February 8, and noted that Musk’s own 2008-model Tesla was strapped to the top of it.
The car, propelled by the Falcon, was pushed into an orbit around the Sun and, once the launch sequences and a final propellant burn to establish trajectory were completed, was essentially left to its own devices, with no course corrections planned. According to calculations lodged by SpaceX with NASA’s Jet Propulsion Laboratory, the Tesla – known formally as Target Body 143205 – will reach a distance of about 257 million kilometres from the Sun before slowly heading back again to eventually complete its first whole orbit.
It will be the first of many. In a paper posted on the preprint site Arxiv, Rein and some colleagues reveal a set of detailed calculations to determine what the very, very long term future is likely to hold for the car, and how likely it might be to wallop into something: the Earth, perhaps, or some other planet.
To do this, the scientists constructed simulations of how the car’s orbits are likely to change over time. In their calculations, they factored in many possible perturbations that could be caused by factors such as the car getting close to planets, and the Yarkovsky effect – the impact of thermal photons, which causes meteorites to drift a little from their paths. {%recommended 6671%}
Over all, they suggest, the Roadster will behave very much like the near-Earth asteroid (NEA) is rather resembles (except, of course, real NEAs aren’t generally car-shaped, don’t contain mannequins and aren’t shaking slightly to the sounds of David Bowie). Most NEAs end up going nowhere near anywhere important – given that planets are truly minuscule in proportion to all the empty space in the solar system – and eventually, after a few million years, collide with Sun.
This will also happen to the Tesla – an ending that will truly make a mess of its paintwork. Before that happens, however, it has a very long journey in front of it.
Its early orbits will bring it into close proximity to the Earth – the first such encounter occurring in 2091. It almost certainly, definitely, probably won’t smack into a bit of farmland somewhere, bit if it’s going to, that will be the year.
As the number of orbits increases, so too will the gradual eccentricity of the trip, and after a while the car will veer away from its home planet and start to whizz by others before eventually zapping into the Sun in “a few tens of millions of years”.
Rein and his colleagues estimate the chance of Musk’s Roadster hitting the Earth in the next three million years at 6%. The chance of it smacking into Venus is 2.5%. Future Mars colonists needn’t worry. Rein and his colleagues report that although their modelling showed several close encounters between red car and red planet, “none of them resulted in physical collision”.
