Rosetta enters orbit around Churyumov–Gerasimenko, September 10, 2014

Data as of 2026-10-14

The instant

Instant (UTC)
September 10, 2014, 09:01:28 UTC
Distance from the centre of Churyumov–Gerasimenko
29.3 km
Speed relative to Churyumov–Gerasimenko
16 cm/s

This is the first instant at which Rosetta, inside the sphere of influence of Churyumov–Gerasimenko, no longer has the energy to escape its pull. An orbit insertion announced by an agency is a manoeuvre that lasts; this instant is a point within it, not necessarily its start.

The mass of Churyumov–Gerasimenko is published with an uncertainty of 0.03 %; across it, this instant moves by less than a second.

The manoeuvre

A manoeuvre detected on the same trajectory, by another method (the trajectory departing from a coast under gravity alone), falls 2 min after this instant.

In Galaxy

Open Rosetta at this instant, at true scale

Pages of the spacecraft and of the body:

How it is measured

The position and velocity of the spacecraft relative to the body are read from Horizons every hour across its stay in the sphere of influence, then every minute and every second around the first hour at which its energy, half the square of its speed minus the mass of the body times the gravitational constant over its distance, is negative. The mass is the one Galaxy displays for the body.

Source

NASA/JPL Solar System Dynamics, Horizons System. Read on October 14, 2026.

Trajectory solution cited by Horizons: rosetta_merged

All orbit insertions