Atom & Cosmos

NASA’s plans to sample an asteroid, good-bye to Spirit rover, Neptune’s spin and more in this week’s news

NASA’s first asteroid sampler The first U.S. spacecraft to scoop up samples of an asteroid and return them to Earth will be launched in 2016, NASA announced May 25. The craft, known as OSIRIS-REx, will reach the near-Earth asteroid 1999 RQ36 in 2020. After the craft studies the space rock — a leftover from the birth of the solar system — from a distance of 4.8 kilometers for six months, scientists will determine the best place to grab a sample. The craft will then move closer to the asteroid and extend a robotic arm to collect more than 57 grams of material. The craft is expected to return the sample to Earth in 2023 . —Ron Cowen Finding Neptune’s spin Figuring out how quickly a big blob of gas rotates isn’t easy, but a planetary scientist has now done it for Neptune. By tracking features on the planet’s surface over the past two decades, Erich Karkoschka of the University of Arizona reports that it rotates every 15.97 hours — a more precise measurement than the 16.11-hour estimate gathered by the Voyager 2 spacecraft. The new data suggest that Neptune’s core must be more massive than scientists had thought, Karkoschka writes in an upcoming Icarus. Alexandra Witze Mid-life crisis for Milky Way Both the Milky Way galaxy and its nearest large spiral neighbor, Andromeda, appear to be in the midst of a crucial transformation, with their average color midway between blue, which denotes youth, and red, which indicates an aging population. Surveys suggest that other galaxies in this betwixt-and-between state, known as the green valley, will have ceased nearly all star formation in a few billion years. The finding reveals the possible future of Andromeda and our home galaxy and opens a new window for studying global changes in galaxies up close, astronomers based in Australia report in an upcoming Astrophysical Journal . —Ron Cowen

NASA says farewell to Spirit
NASA has halted attempts to communicate with the Mars rover Spirit, which fell silent on March 22, 2010, as winter approached and the rover’s solar energy supply dwindled. The space agency announced its decision on May 25. Spirit operated for six years following its January 2004 landing, returning to Earth more than 124,000 images and driving a total of 7.73 kilometers, more than 12 times its travel goal. The rover discovered silica deposits, a sign that Spirit’s landing site once had hot springs or steam vents that may have supported microbial life. Spirit’s twin, Opportunity, remains active and in relatively good condition on the Red Planet. —Ron Cowen

FIELD TRIP The OSIRIS-REx spacecraft will rendezvous with asteroid 1999 RQ36, extend a sample collecting device and return about 60 grams of material to Earth for analysis. NASA, GSFC, Univ. of Arizona

Hale-Bopp comet won’t die
Comet Hale-Bopp, which wowed observers when it neared the sun in 1997, is still showing signs of activity even though it now lies beyond the orbit of Neptune. New observations, the most distant ever taken of any comet, indicate that despite the body’s great distance from the sun and lack of a visible shroud of dust, Hale-Bopp may still be shedding material, rather than being frozen to death. It’s unclear how and when all activity will finally cease, an international team of astronomers reports in an upcoming Astronomy & Astrophysics. —Ron Cowen

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