Speeding Comet for Rosetta Mission Releases 2 Cups of Water Every Second

Scientists are learning a bit more about Comet 67P/Churyumov-Garasimenko. It turns out that the comet is releasing the equivalent of two glasses of water into space every second as it speeds along its path. The findings are crucial as the European Space Agency's Rosetta spacecraft prepared to be the first to orbit a comet in August.

The researchers first detected the water vapor using the Microwave Instrument for Rosetta Orbiter (MIRO) when the spacecraft was about 217,000 miles away from the comet. At the time, the comet was about 363 million miles away from the sun. After this initial discovery, water vapor was detected every time the MIRO instrument was pointed toward the comet.

"We always knew we would see water vapor outgassing from the comet, but we were surprised at how early be detected it," said Sam Gulkis, principal investigator of the MIRO instrument. "At this production rate, comet 67P/Churyumov-Gerasimenko would fill an Olympic-size swimming pool in about 100 days. But, as the comet gets closer to the sun, the gas production rate will increase. With Rosetta, we have an amazing vantage point to observe these changes up close and learn more about exactly why they happen."

Currently, Rosetta is about halfway between Mars and Jupiter, which is about 261 million miles from Earth. This comet is a bit like a time capsule, containing primitive material left over from when the stars and its planets first began to form. By studying the gas, dust and structure of the nucleus associated with the comet, Rosetta can send back key findings to scientists about the beginnings of our galaxy.

"Our comet is coming out of its deep-space slumber and beginning to put on a show for Rosetta's science instruments," said Matt Taylor, Rosetta's project scientist. "The mission's engineers will be using this MIRO data to help them plan for future mission events when we are operating in close proximity to the comet's nucleus."

Currently, the researchers plan to have the spacecraft land on the comet on November 11.