Launched on Sept. 8, 2016, NASA’s OSIRIS-REx spacecraft is heading out into the main asteroid belt beyond the orbit of Mars to meet up with the 1,600-foot-wide asteroid Bennu. Ultimately OSIRIS-REx will map and collect a sample of Bennu’s surface, returning it to Earth in 2023. But while it’s still traveling through near-Earth space in preparation for a gravity-assist flyby this September, mission scientists will take advantage of OSIRIS-REx’s position near L4 to look for any captured “Trojan” asteroids.
“Scientists predict that there should be more Trojan asteroids sharing Earth’s orbit. These asteroids are difficult to detect from Earth because they appear close to the sun from Earth’s point of view,” writes OSIRIS-REx principal investigator Dante Lauretta at the University of Arizona. “In mid-February 2017, however, the OSIRIS-REx spacecraft will be positioned in an ideal spot to undertake a survey. We have decided to take advantage of this favorable position to perform a search for Trojan asteroids in the Earth-Sun L4 region. We will use the OCAMS MapCam imager to image a portion of the volume of space where we expect the Earth Trojan asteroids to reside.”
Currently only one Trojan asteroid—2010 TK7—has been confirmed in Earth orbit, but more are expected.
Read more on the principal investigator’s blog: Searching for the Earth-Trojan Asteroids, and watch a video below from Dr. Jim Green, NASA’s Director of Planetary Science.