6 August 2014 – One year ago today ESA’s Rosetta spacecraft rendezvoused with comet 67P/Churyumov–Gerasimenko out between the orbits of Mars and Jupiter, over 400 million kilometres from Earth.

As the comet’s gravity is so minimal – if you were standing on 67P’s surface you could easily throw a ball upwards faster than its escape velocity, IE it would never come back down again! – Rosetta couldn’t just insert into a normal elliptical orbit, but instead had to perform a series of triangular-shaped orbits, making periodic engine burns to gradually work its way down to an orbital height of around 30 kilometres a month later.

Artist impression of ESA's Rosetta approaching comet 67P/Churyumov-Gerasimenko. The comet image was taken on 2 August 2014 by the spacecraft's navigation camera at a distance of about 500 km. The spacecraft and comet are not to scale.
Artist impression of ESA’s Rosetta approaching comet 67P/Churyumov-Gerasimenko.
The comet image was taken on 2 August 2014 by the spacecraft’s navigation camera at a distance of about 500 km.
The spacecraft and comet are not to scale.

Image source: http://www.esa.int/spaceinimages/Images/2014/08/Rosetta_arrives_at_comet