Simulation of the Rosetta fly-by of asteroid Steins.
Rosetta fly-by of asteroid Steins - September 2008
Data from the JPL solar simulator and the JPL Horizons system were used to generate this animation illustrating the orbit of Rosetta (green line) and asteroid Steins (orange line). It starts shortly after the last Earth gravity assist (in November 2007) and continues through the Steins fly-by to just before the next Earth gravity assist manoeuvre (November 2009).
The closest approach between Rosetta and the asteroid was on 5 September 2008 at 18:38 UTC(*). At this time the spacecraft was 800 km from the asteroid and flew past at a relative speed of 8.6 km/s.
(*)The animation indicates closest approach at 18:37 UTC - this was based on the estimates available at the time.