The landing was part of a $1.3 billion, 10-year mission known as Rosetta, led by the ESA with the cooperation of a consortium including NASA. The aim is to study the composition of comets, as well as their interaction with the solar wind.
“It is sitting on the surface,” said Philae lander manager Stefan Ulamec. “Philae is talking to us — we are on the comet.”
Philae Lander: A complicated descent
The Philae lander was released from the Rosetta spacecraft, which has been tracking the comet since August. Scientists have been planning the landing for the past few months, an incredibly difficult task due to the weak gravitational pull of the comet, known as Comet 67P/Churyumov-Gerasimenko.
To counteract this, a thruster system was to be employed to hold the lander in place while a set of harpoons were fired into the comet to secure it. Although readings showed that the thruster system was not properly engaged, the landing was still successful.
The Philae lander may only be the size of a washing machine, but according to the ESA website it will measure the density and thermal properties of the surface of the comet, and detect and identify any complex organic chemicals present, as well as measuring the magnetic field and interactions between the comet and the solar wind.
Lead scientist Jean-Pierre Bibring of the Institut d’Astrophysique Spatial, France, claimed that in the future the readings could potentially be compared with information from other planetary systems, to prove whether there is alien life out there. However the first aim of the lander is to carry out analysis of the comet’s ice and dust, some of which is thought to date from the formation of the solar system some 4.5 billion years ago.
The Rosetta spacecraft will continue to monitor the comet from a distance, and is capable of achieving most mission objectives even if the Philae lander should encounter difficulties.