The Rosetta space mission

What is the  nucleus of a comet made off exactly ? This question is very hard to achieve for telescopes on Earth no matter how sophisticated or powerful they are because the nucleus of a comet is very small compared to its distance to Earth and cannot be directly seen from Earth. The atmospheres of comets (coma) are therefore studied in order to deduce the composition of the nucleus with complex chemical models. But things could soon change thanks to Rosetta, a spacecraft developed by the ESA which borders on science fiction. This spacecraft will go in orbit around Churyumov-Gerasimenko, an “old” periodic comet which has been regularly passing near the sun for a very long time. Rosetta will also release a module, by the name of Philae, to land on its surface in order to carry out very precise measurements in situ !  “In our research field, this great first step is like the first step of mankind on the moon”! says Emmanuël Jehin.

Rosetta must not fail and its task will not be easy. It will have to become a satellite of the comet at a distance of a few kilometers and then drop Philae, hoping it will not be destroyed by the jets coming from active regions of the nucleus  which projects dust particules in space at the speed of a bullet…, or missing the target, or bouncing back into space at the moment of landing… Good luck!

If the spacecraft succeeds in its mission, astronomers will be able to compare their telescopic observations to those made in situ. They hope that these observations will complete their theories which have been constructed during long years of research. TRAPPIST will also observe Churyumov-Gerasimenko, particularly when it arrives at its perihelion in 2015. “TRAPPIST is part of a network of telescopes which will closely follow the activity of the comet in order to better plan and complete the observations of Rosetta. We are hoping we can play an important role in this new venture and help to find new pieces of the big puzzle to understand the formation of the solar system”! concludes the astronomer from Liege.