Rosetta spacecraft arrives at comet after 10-year chase

August 6, 2014

After a decade of travel, the European Space Agency's Rosetta spacecraft arrived at a comet early this morning.

"Ten years we've been waiting in the car to get to scientific Disneyland," ESA's Mark McCaughrean said. "It's a wonderful moment."

The comet, called 67P/Churyumov–Gerasimenko, orbits the sun once every six years or so. It's an unusual shape — some say it looks like a rubber duck, others like the spaceship "Serenity" from the sci-fi series Firefly.

Rosetta will now stay with the comet as it travels around the sun. The spacecraft's scientific instruments will be used to probe everything from the dust thrown up by the comet, to its internal structure.

One of the instruments, a spectrometer named "Alice," was developed to measure the properties of light by the Southwest Research Institute in Boulder. A press release from the institute describes just what Alice will do: 

"Soon it will spend hundreds of days in orbit around Churyumov-Gerasimenko, analyzing the composition of its atmosphere, mapping its surface, and studying the properties of fine dust particles coming off the comet. It will be the first ultraviolet spectrograph ever to examine a comet,” says Dr. Alan Stern, Alice principal investigator and an associate vice president of the SwRI Space Science and Engineering Division.

The shoebox-sized, high-tech Alice is a highly miniaturized UV imaging spectrograph with more than 1,000 times the data-gathering capability of instruments flown a generation ago, yet it weighs less than 4 kilograms and draws just 4 watts of power.

In November, Rosetta will release a lander about the size of a small refrigerator. The lander will float down to the comet's surface and attempt to secure itself using harpoons. Harpooning a comet would be a first for humanity.

Ultimately, researchers say studying comet 67P should teach them more about the origins of the solar system. Comets are thought to be leftover raw ingredients from when our sun and the planets formed. They may even have brought the water in Earth's oceans — seeding the planet for the birth of life itself.

"A comet is made up of lots of frozen ices and when it's further out in the solar system it's just a big ball of ice and some rock and no tail," Doug Duncan, director of the Fiske Planetarium in Boulder, told "Colorado Matters" last month. "And as it gets close it starts to vaporize and these different gases come off of it, and we've never really been able to study that up close and personal."

Here's a look at the long and circuitous route Rosetta took to arrive at its destination:

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