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Emily Lakdawalla • May 15, 2014

Pretty pictures: Rosetta's comet is now acting like one!

As Rosetta crosses the last couple million kilometers separating it from its target comet, the spacecraft is snapping away with its OSIRIS camera. They take these images primarily for optical navigation -- to help steer toward the destination. But the photos have also caught the comet beginning to act like a comet, throwing off gas and dust to develop a coma that is already 1300 kilometers across, and growing. All this from a nucleus only 4 kilometers across.

Comet Churyumov-Gerasimenko develops a coma, March 27 to May 4, 2014
Comet Churyumov-Gerasimenko develops a coma, March 27 to May 4, 2014 A sequence of images showing comet 67P/Churyumov–Gerasimenko moving against a background star field in the constellation Ophiuchus between 27 March and 4 May 2014, as the distance between the spacecraft and comet closed from around 5 million to 2 million kilometers. The comet (and Rosetta) were between 640 million km and 610 million km from the Sun during the sequence. The comet is seen to develop a dust coma as the sequence progresses, with clear activity already visible in late April. Exposure times are 720 seconds for each image, taken with the OSIRIS Narrow Angle Camera. The globular cluster M107 is also clearly visible in the field of view.Image: ESA / Rosetta / MPS for OSIRIS Team MPS / UPD / LAM / IAA / SSO / INTA / UPM / DASP / IDA

Here's a zoomed-in look at the comet on April 30:

Comet 67P/Churyumov-Gerasimenko on April 30, 2014
Comet 67P/Churyumov-Gerasimenko on April 30, 2014 As Rosetta approached, cometary activity began on 67P/Churyumov-Gerasimenko. The coma extends over 1300 kilometers from the nucleus.Image: ESA / Rosetta / MPS for OSIRIS Team MPS / UPD / LAM / IAA / SSO / INTA / UPM / DASP / IDA

Rosetta is now matching paces with the comet. The next rocket maneuver, a very large one, is planned for May 21. More information on ESA's website!