Comet was probably part of oldest meteorites

Chury: A chunk off an old meteorite block? University of Bern

Swiss scientists believe that the comet Churyumov-Gerasimenko is related to the oldest-known meteorites in our solar system. 

Researchers at the University of Bern announced their hunch on Wednesday, based on elements identified by the Rosetta Orbiter Spectrometer for Ion and Neutral Analysis (ROSINA). 

On the comet’s surface, the device found sodium, silicon, potassium, calcium and magnesium – elements well-known in meteorite research and particularly abundant on carbonaceous chondrites, the oldest class of meteorites. 

“So a relationship between Chury and such meteorites makes sense,” according to Peter Wurz of the University of Bern’s Center for Space and Habitability. The ROSINA device was developed and constructed by an international consortium under the direction of the university’s physics institute. Seven cameras on board the lander, Philae, provide panoramic vision and capture stunning images. These include selfies of the probe with Mars and the comet in the background.

Wurz and his team are studying how the solar wind affects the atmosphere and surface of Chury. As the comet orbits the sun, it has to pass through this solar wind – a steady stream of electrically charged particles. 

When these particles hit the comet’s surface, they cause a process called “sputtering”, in which atoms are dislodged and released into space. 

The Swiss researchers feel lucky to have observed the release of these elements because it was a rare opportunity. Once Chury gets closer to the sun, its atmosphere will become denser and better able to deflect the particles carried by the solar wind, which means no surface elements will be shaken up.