Seven years ago this week, Rosetta swung by Mars on one of four gravity assist manoeuvres needed to boost the spacecraft onto its trajectory towards comet 67P/Churyumov-Gerasimenko (the other three gravity assists were at Earth).
On 24 February 2007, Rosetta acquired the above image at a distance of about 240 000 km, while on the approach to Mars. It is a true-colour image generated using the OSIRIS orange (red), green and blue colour filters.
Rosetta’s closest approach to Mars was just 250 km, at 02:15 UT on 25 February. Rosetta’s Philae lander took the image shown right 4 minutes before closest approach, at a distance of 1000 km. It captures one of Rosetta’s 14 m-long solar wings, set against the northern hemisphere of Mars, where details in the Mawrth Vallis region can be seen.
Mawrth Vallis is of particular interest to scientists because it contains minerals formed in the presence of water – a discovery made by ESA’s Mars Express.
The image was originally taken in black-and-white; representative colour was added to the surface of Mars and, in this version, these colours have been slightly enhanced, along with some brightening of details in the solar wing.
Also on this day, but in 2004, Rosetta rolled out to the launch pad, ahead of an originally planned launch date of 26 February. In the end the launch took place on 2 March – ten years ago this coming Sunday!