Europe’s Rosetta spacecraft reaches its final destination Wednesday after a decade-long journey into deep space that aims to place the first lander on a comet.
Rosetta will begin orbiting the Churyumov-Gerasimenko comet to glean information about the mass of dirty ice, dust and gas, according to the European Space Agency, which launched the probe in 2004. In November, it’s due to send a smaller landing craft down onto the comet to take more measurements.
“This is the start of the real mission that Rosetta was built for – it’s the kickoff of the real science phase,” said Gerhard Schwehm, an ESA consultant and manager of the mission from its liftoff until he retired last year. “We’re at the comet and now starting to monitor it and study it in detail.”
Scientists hope to learn about the early evolution of the solar system by studying comets, which date back 4.6 billion years, when the planets were forming. Researchers also are searching for organic molecules that represent the building blocks for life, which comets may have brought to Earth in its early years.
“It’ll help us to model better the evolution of the planets out of the presolar nebula,” Schwehm said by phone from ESA’s mission control in Darmstadt, Germany. “There will be a lot of information that helps us understand how processes worked and what happened 4 1/2 billion years ago. It’s information from the infancy of our solar system.”
The Rosetta mission is the first attempt to orbit and land a probe on a comet. ESA’s first deep-space mission, Giotto, was sent to investigate Halley’s Comet in 1986. The U.S. National Aeronautics and Space Administration has also launched two missions to study comets in the past 20 years.
Rosetta is due to perform a final slowing maneuver shortly after 11 a.m. Darmstadt time Wednesday. That will place the craft in an initial triangular orbit about 60 miles from the comet, according to Schwehm. Because signals from the spacecraft take more than 20 minutes to reach Earth, an announcement is likely about 11:30 a.m., he said.
Instruments aboard the orbiter and the lander will measure the chemical composition of the comet, its density and how strong the surface is. They’ll also monitor gases and dust ejected by the comet. The landing craft, Philae, is due to land around Nov. 11. It will be able to drill about 8 inches into the comet, Schwehm said.