What will happen to Starman?

When Elon Musk’s Tesla Roadster with Starman launched on February 6, 2018, it entered orbit around the Sun, crossing the paths of both Earth and Mars. We can study the long term evolution of Starman based on the physics that tracks the long term history of asteroids.

The way that this can be determined is to create a simulation with slightly randomized inputs and play it forward, taking into account things like the gravity of the planets. Astrophysicists Hanno Rein, Daniel Tamayo, and David Vokrouhlický used a program called REBOUND that does just that, using Starman as their test subject. They determined that the Roadster’s orbit has a Lyapunov timescale, or time before it becomes chaotic, of only a few decades. Beyond a century or two, minuscule uncertainties of just a few meters in initial position grow exponentially. JPL Horizons currently only projects Starman’s life for about 80 years because of this, beyond that the uncertainty is just too high.

To make this work many tiny variations of the initial orbit are played with a realistic physics simulation over millions of years. To make it easier they are grouped together, requiring fewer calculations. Over millions of years the orbits will subtly shift, as you can see yourself in this simulation below.

Interactive Simulation

Explore the fate of Starman with 100 different possibilities over 15,000,000 years below.

Key Takeaways

• Hitting a planet The most likely impact targets are Earth (~22%) and Venus (~12%).
• Sular Plunge: Sometimes these encounters will lead to lower orbits, eventually leading to a collision with the Sun (~12%).
• Long-Term Survival: According to this simulation over 15 million years, approximately half (~50–55%) of all simulated clones remain safely in orbit around the Sun
• Solar System Ejection: Occasionally Starman could be booted out of the Solar System by a close approach of Jupiter, but this is very rare, happening less than 1% of the time. This is so rare because the initial orbit lies quite far from Jupiter’s gravitational reach.