European Space Agency's (ESA) comet chaser, Rosetta space probe has made a discovery with the comet, 67P or Churyumov-Gerasimenko, which in latest reports sent by Rosetta spacecraft has an unusual ice cycle. The rotation of the comet happens once every 12 hours, which means that at some point in its rotation; different parts of the comet are in the shadow, a factor for cooling. The other side on the other hand has ice accumulation being vaporized. Most likely, according to the scientists, the odd shape of the comet might be due to the ice formation corroding the surface of the space rock.
An instrument on board Rosetta that took the measurements, it seemed that the sunlight that hits the comet causes for water vapor deep inside 67P to rise to its surface. This then accumulate into an icy layer when the sun goes down, and when the sun "rises" again in the mornings, it will vaporize the ice layer. The following findings may lead in understanding all comets in our solar system, Scientists said.
The accumulation of the substance, in this case the water vapors on the comet, is an important factor that might have been essential for life to thrive on the comet. The amount of water which Rosetta measured might also say something about comets like 67P providing the seeds for life on Earth. Scientists are very excited to study more about the cycle on other comets as well, provided that they do have one like 67P has.
In a journal published in Nature, changes of surface temperature in the comet seem to be the driving force of water. "The water ice in the uppermost surface layers will be stable until a new cycle of solar illumination starts which will increase the surface temperature and thus trigger again the outgassing of water from the comet," Dr Maria Cristina De Sanctis, an astrophysicist at the Institute for Space, Astrophysics and Planetology in Rome, and her colleagues, writes in Nature.
