Comet 67P/Churyumov-Gerasimenko is rousing.
Shown here in this series of images from the OSIRIS narrow-angle camera on ESA’s Rosetta spacecraft, the nucleus of Comet C-G is developing its dusty coma. The images were taken from March 27th to May 4th, and by the end of the sequence the coma was about 1,300 kilometers (800 miles) in radius. The coma grows as the dirty iceball bears down on the Sun, the rising temperatures evaporating carbon dioxide and water ices, as well as other volatiles, on the nucleus’s surface.
The comet’s nucleus is only 4 km across, but the coma may eventually extend hundreds of thousands of kilometers as it whips through its closest approach to the Sun in August 2015.
The Rosetta spacecraft took the last of these images from a distance of roughly 2 million kilometers as it makes its way toward the comet. The craft will rendezvous with Comet C-G this August and deploy its lander, Philae, to the nucleus’s surface in November. If all goes according to plan, the spacecraft will travel with the comet from August 2014 through perihelion, closely watching as the nucleus suffers the rising onslaught from solar heating.
Read more about the waking comet in the ESA press release. And this summer keep an eye out for our August 2014 issue, where we’ll have an in-depth article on the Rosetta mission.