What a Way to Go: Spacecraft to Crash-Land on Eros

The first spacecraft to orbit an asteroid will take a one-way trip to its surface Feb. 12, crashing into the boulder-strewn asteroid Eros at about 7 mph, NASA said.

The $223-million mission has taken the Near Earth Asteroid Rendezvous spacecraft to within 930 miles of Eros, a small asteroid 196 million miles from Earth.

The spacecraft met all its goals during its five-year mission, so scientists decided to crash-land it on Eros to take close-up pictures of the 21-mile-long asteroid’s surface.

“We’re trying to find some way to end the mission on a high note,” said Bob Farquhar, mission director at Johns Hopkins Applied Physics Laboratory in Laurel, Md.

The effort will be the first time the National Aeronautics and Space Administration has tried a “controlled landing” with a spacecraft designed only as an orbiter.

Data taken during the mission include X-ray, gamma-ray and infrared readings on its composition and about 160,000 photo images of its surface.

Research derived from the data will take several more years to analyze, yet several discoveries have surprised scientists so far, including the large-scale movement of fine surface material downhill--akin to erosion--that was unexpected given Eros’ low gravity.

Scientists were also surprised by Eros’ low sulfur content, suggesting it may have been heated in the past, causing its sulfur to evaporate.