Executive summary: its orbit is not very stable. Photo courtesy of SpaceX On February 6, 2018, SpaceX performed its test launch of its new Falcon Heavy rocket. It was a very successful launch. As most people know, the payload was Elon Musk's 2008 Tesla Roadster . After orbiting the Earth for a few hours, the upper stage lit up again and sent the Tesla on a Solar orbit: Musk has famously tweeted that the Tesla will be orbiting for "a billion years." This is extremely unlikely. In fact, it will likely crash into the Sun, or a planet (most likely Earth but perhaps Venus), or be ejected from the Solar System. To try to characterize this, I went to NASA's JPL Horizons web page to get current Cartesian elements for the Tesla (these are vectors of position and velocity). These are the elements as of today, February 10, 2018: 2458159.500000000 = A.D. 2018-Feb-10 00:00:00.0000 TDB X =-7.690802173107607E-01 Y = 6.236475652855626E-01 Z =-1.393643118679943E-03 ...