Rosetta’s Comet Gets an Early Start

Comet 67P has gotten close enough to the sun to start sizzling.

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An artist's impression shows the Rosetta and its lander approaching a comet as it comes alive from the sun's heat.

A spacecraft named Rosetta has been on the chase for Comet 67P/Churyumov-Gerasimenko for over a decade. After nearly three years in hibernation in deep space while it cruised closer and closer, the spacecraft woke up to much fanfare on January 20. Now it seems the comet it’s pursuing has woken up too.

According to European Space Agency, the comet is now much brighter than the last time it was observed—it has been behind the sun from our vantage point since last October. Since the comet has been rounding its farthest point from the sun in its orbit, it’s been frozen and inactive. Yesterday’s press release says, “Although it is also now nearer to Earth, it has brightened faster than expected for an inactive comet of this size, suggesting that its icy nucleus has started to evaporate as it moves gradually closer to the Sun.”

Rosetta will rendezvous with and eventually go into orbit around the comet this fall, releasing a lander named Philea to touch down on the surface—the first ever landing on a comet. Air & Space contributor Guy Gugliotta’s article on Rosetta’s comet chasing mission will appear in our April/May issue, which goes online next week. Here’s a preview:

In December, the inbound comet will get within 400 million miles of the sun.... Here, the sun’s heat will start to bring it alive. Gas jets will belch from its surface, and a hazy atmosphere called a coma will form from ice and dust, and stretch out to become an incandescent tail. For the next month and perhaps longer, Philae will ride Churyumov-Gerasimenko like a bronco buster, “not bothered too much by all this,” [mission manager Fred] Jansen says, and Rosetta will escort the two, transmitting data from its 11 instruments and the 10 on the lander.

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