Orbit tracking

The car and the upper stage were passivated by intentionally removing remaining chemical and electrical energy, at which point they ceased transmitting telemetry. Based on optical observations made using a robotic telescope at the Warrumbungle Observatory, Dubbo, Australia and refinement of the orbit, a close re-encounter with Earth (originally predicted for 2073) is not possible. In October 2020 the car made a close approach to Mars, about 8 million kilometres (5 million miles) away, well outside the planet's gravitational sphere of influence.

The Virtual Telescope Project observed the Tesla two days after its launch, where it had a magnitude of 15.5, comparable to Pluto's moon Charon. The Roadster was automatically spotted and logged by the Asteroid Terrestrial-impact Last Alert System (ATLAS) telescope operated by the University of Hawaii. The car was observed by the Deimos Sky Survey (DeSS) at a distance of 720,000 km (450,000 mi) with a flashing effect suggesting spinning.

Through measuring changes in apparent brightness of the object, astronomers have determined that the Roadster is rotating with a period of 4.7589 ± 0.0060 minutes (i.e. 4 minutes, 46 seconds). By February 11, 2018, astrometry measurements from 241 independent observations had been collated, refining the positions to within one-tenth of an arcsecond and published by the SeeSat-L mailing list, a group of amateur satellite spotters—more accurate than for most observations of objects in space.

Future predictionsedit

Simulations over a 3-million-year timespan found a probability of the Roadster colliding with Earth at approximately 6%, or with Venus at approximately 2.5%. These probabilities of collision are similar to those of other near-Earth objects. The half-life for the tested orbits was calculated as approximately 20 million years, but with trajectories varying significantly following a close approach to the Earth–Moon system in 2091.

Musk had originally speculated that the car could drift in space for a billion years. According to chemist William Carroll, solar radiation, cosmic radiation, and micrometeoroid impacts will structurally damage the car over time. Radiation will eventually break down any material with carbon–carbon bonds, including carbon fiber parts. Tires, paint, plastic and leather might last only about a year, while carbon fiber parts will last considerably longer. Eventually, only the aluminum frame, inert metals, and glass not shattered by meteoroids will remain.

Potential followup missionedit

In August 2019, as the Roadster completed its first orbit around the Sun, Musk stated that SpaceX may one day launch a small spacecraft to catch up with the Roadster and take photographs.