August 2014: Rosetta arrives at Comet 67P
After a ten-year voyage through space, in August 2014 Rosetta finally approaches its target comet. The team is expecting to see that the solid, central part of the comet – its ‘nucleus’ – is shaped like a potato. The images that come down showed something completely different.
Claire Vallat, who was planning the mission science at the time says: “When we received the first detailed image of the nucleus I was on holiday but frenetically checking my phone for any new OSIRIS images whilst we were approaching Comet 67P.” OSIRIS was Rosetta’s camera, which gave us our first view of the comet.
“This was a very exciting moment since the nucleus shape did not look at all like how we envisaged it until then: it had two lobes rather than being potato-shaped! I remember thinking that it would be extremely challenging to land Philae on such a complex object, but very exciting too.”
For Geraint Jones, who went on to propose ESA’s Comet Interceptor mission, the first view of Rosetta’s comet came as a surprise for a different reason: “It was during the summer, I was on holiday and I had no internet access. So I actually saw the shape of the comet for the first time on a newspaper stand in Germany!”
Geraint was amazed to see the incredible level of detail in the images, with intricate landforms and bizarre terrain.
Nick Thomas, who was on Rosetta’s OSIRIS camera team, adds: “What you have to recall is that Rosetta took a while to reach the comet. Data was being taken already when it was still just a distant dot. This is a rather slow process, with the comet getting bigger and bigger. It suddenly became very real when we were able to take a movie of this thing for the first time, and we saw this dual object – that was staggering, it told us we were there, and we were going to find something special.”
The arrival of Rosetta was perfect timing for plasma scientist Charlotte Götz, who started her PhD that same month. Charlotte was one of the first to work with data arriving from the mission. “One thing I remember was that during these first weeks and months, people were super excited – some people had waited for this data for 30 years, since Giotto!” says Charlotte. Launched in 1985, Giotto was ESA’s first and only previous comet mission.