Rosetta probe set to make closest encounter with target comet's surface

ESA's Rosetta probe is set to fly rather close to Comet 67P Churyumov-Gerasimenko on 14 February, passing just 6 km from the surface.

The probe will start a new orbit of the comet on February 7, first moving out by 140 kilometers before getting as close as six kilometers away on February 14.

The flyby will take Rosetta over the most active regions of the comet, helping scientists to understand the connection between the source of the observed activity and the atmosphere, or coma.

In particular, they will be looking for zones where the outflowing gas and dust accelerates from the surface and how these constituents evolve at larger distances from the comet.

The comet's surface is already known to be very dark, reflecting just 6 percent of the light that falls on it.

During the close flyby, Rosetta will pass over the comet with the Sun directly behind, allowing shadow-free images to be collected. By studying the reflectivity of the nucleus as it varies with the angle of the sunlight falling on it, scientists hope to gain a more detailed insight into the dust grains on the surface.