The European Space Agency's Rosetta probe has made its first foray on to the dark side of Comet 67P, revealing significant changes from the sunny northern hemisphere.
The European Space Agency’s Rosetta space probe has been orbiting comet 67P for quite some time, sending valuable information about the strangely shaped body back to Earth on a constant basis. According to a report from Astronomy.com, astronomers have finally gotten up close and personal with a part of the comet they have never witnessed before: the dark side.
Rosetta reached a particular point in its seasonal orbit of the comet that has allowed it to see the hemisphere shaded from the sun, revealing mysterious surface topography and a whole new set of areas on the comet to study. The probe orbits the comet once every 6.5 years.
The northern hemisphere of the comet faces the sun for over 5.5 years, resulting in a seriously long summer season. The southern hemisphere experiences winter at the same time, remaining in the dark and cold shadows. As the comet approaches perihelion, the point in its orbit when it is closest to the sun, the southern hemisphere becomes soaked in sunlight for a brief yet warm summer season.
The comet’s northern hemisphere was still in its summer season when Rosetta arrived in August of 2014. For multiple months, the only information Rosetta could gather about the southern hemisphere of comet 67P was by using its Microwave Instrument for Rosetta Orbiter, or MIRO.
As researchers began to look at the comet’s southern hemisphere, they noticed a wide range of changes from the northern hemisphere. The thermal and electrical properties are opposite of those on the sun-drenched northern hemisphere, and the surface material appears to be composed of water and carbon dioxide ice.