Rosetta mission – Comet chaser’s top five discoveries in pics
Rosetta mission – Comet chaser’s top five discoveries in pics
Rosetta mission – Comet chaser’s top five discoveries in pics
On September 30, 2016, the European Space Agency (ESA)'s Rosetta spacecraft ended its 12-year mission to a comet by crash-landing on to the icy object's surface.
Launched in 2004, Rosetta spacecraft arrived at Comet 67P/Churyumov-Gerasimenko on 6 August 2014. It is the first mission in history to rendezvous with a comet, escort it as it orbits the Sun, and deploy a lander - Philae - to its surface.
During its mission, Rosetta made many surprising discoveries, helping scientists to unlock the secret nature of comet. Here are some amazing discoveries from Rosetta's monumental comet encounter:
Oxygen on comet 67P
For the first time, molecular oxygen has been detected in the gas cloud around comet 67P, which scientists described as the most surprising discovery about the comet to date.
“We weren’t really expecting to detect O2 at the comet - and in such high abundance - because it is so chemically reactive, so it was quite a surprise,” says Kathrin Altwegg, principal investigator of the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis instrument, ROSINA.
During its mission to the comet, the probe detected an abundance of different gases pouring from its nucleus.
Active pits on Rosetta`s comet
Cavities measuring up to a few hundred meters in diameter have been found under the surface of comet 67P/Churyumov-Gerasimenko. Researchers under the lead of Jean-Baptiste Vincent from the MPS studied 18 peculiar pit-like depressions all occurring in the northern hemisphere of comet 67P.
They said some of the dust jets emitted from comet can be traced back to active pits on its surface.
Building blocks of life found among organic compounds on Comet 67
Seasonal cycle of water ice at comet
Scientists working with the Rosetta discovered that the amount of water ice on the surface of comet comet 67P/Churyumov–Gerasimenko regularly changes.
The image taken by Rosetta depicts seasonal cycle of water ice at the comet - the colour of visible light reflected by Comet 67P on 1 August 2014 (left), shortly before Rosetta arrived at the comet, and a year later, on 30 August 2015 (right), shortly after the comet’s closest approach to the Sun.