According to the European Space Agency (ESA), Rosetta’s original mission was to study the comet 67P/Churyumov-Gerasimenko. However, the ESA planned its route so it would be able to study the asteroid Lutetia. The instruments on the spacecraft, designed by NASA, made measurements that should help scientists derive the mass of the object, understand the properties of the asteroid’s surface crust, and record the solar wind in the vicinity and look for evidence of an atmosphere.
NASA’s instruments were also responsible for this latest batch of images, which excited many astronomers. “Little is known about asteroid Lutetia other than it is about 100 kilometers (62 miles) wide,” said Claudia Alexander, project scientist for the U.S. role in the Rosetta mission, from NASA’s Jet Propulsion Laboratory in Pasadena, California. The spacecraft has passed the asteroid at a minimum distance of 3,160 kilometers (1,950 miles) and at a velocity of 15 kilometers (9 miles) per second, setting records for both parameters.
While Lutetia certainly received its share of scientific attention, it is actually the second time Rosetta and its instruments provided high-quality pictures. The first time was when the spacecraft flew within 800 kilometers (500 miles) of asteroid Steins. Moreover, this was not the first time astronomers acquired images of Lutetia; ground-based telescopes took previous images, but they were of lesser quality.
According to Alexander, past images showed only hints of the asteroid’s shape. “Allowing Rosetta’s suite of science instruments to focus on this target of opportunity has greatly expanded our knowledge of this huge space rock, while at the same time is gave the mission’s science instruments a real out-of-this-world workout,” she said.
The Rosetta spacecraft was equipped with an ultraviolet instrument, a plasma instrument, a microwave instrument, and portions of the electronics package for the double focusing mass spectrometer of the Rosetta orbiter sensor for ion and neutral analysis. According to NASA, the Lutetia flyby is the final scientific milestone for Rosetta before it goes into hibernation, scheduled for early 2011. Three years later, in 2014, the controllers will remotely “wake” the spacecraft and have readied for comet 67P/Churyumov-Gerasimenko.
TFOT has also covered the Hubble telescope’s capturing of a rare Jupiter collision, and the magnificent tail of Comet McNaught, captured at Siding Spring Observatory in Australia. Other related TFOT stories include the rare observation of celestial fireworks occurring 20,000 light-years away in the constellation Carina, and the explosion of a star, captured by NASA’s space telescope Swift.
For more information about the Rosetta spacecraft and its flyby near Lutetia, see NASA’s press release.