Rosetta Finds Comet is Melting Faster Than Ever

New data from the European Space Agency's (ESA) Rosetta spacecraft has been revealed, showing that the spacecraft's comet host is shedding a lot more water than expected as it draws closer to the Sun. 

Way back in July 2014, the Rosetta spacecraft was just closing in on the comet, 67P/Churyumov-Gerasimenko, now often referred to as the "rubber ducky" comet. Still more 200,000 miles away, Rosetta was able to reveal that the ducky was "sweating" as it drew closer to the Sun in a long, elliptical orbit.

That "sweat" - water and dust shed from 67P - showed how the comet is susceptible to the warmth of the Sun, where its frozen nucleolus was slowly melting away about 300 mL of water a second - that's about the equivalent of two small glasses of water.

Now, half-a-year later, 67P has continued to slowly spiral towards the Sun. With things heating up, new data from Rosetta (now closely orbiting the comet) has found that that melt rate has gone from glasses to buckets, with the comet shedding about 1.2 liters (L) of water into space every second.

This was determined by NASA's Microwave Instrument for Rosetta Orbiter (MIRO), aboard Rosetta, and was recently revealed in a comprehensive overview of Rosetta data published in a special issue of the journal Science.

"In observations over a period of three months [June through August, 2014], the amount of water in vapor form that the comet was dumping into space grew about tenfold," Sam Gulkis, the principal investigator of the MIRO instrument at NASA's Jet Propulsion Laboratory, explained in a statement.

"To be up close and personal with a comet for an extended period of time has provided us with an unprecedented opportunity to see how comets transform from cold, icy bodies to active objects spewing out gas and dust as they get closer to the Sun," he added.

Gulkis admits that this revelation was a bit surprising, as it was assumed that it would take much longer for the Sun's heat to affect the comet in such a way. After all, 67P is still far away enough from the Sun that Rosetta will be able to continue to accompany the comet until next August.

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