Ten years ago, the US Congress, remarkably forward, passed a law that required NASA to identify 90 percent of asteroids that were 450 feet or larger and could potentially pose a threat to Earth. Congress gave NASA a 2020 deadline to meet that goal, but the agency won’t meet that goal. The agency has a valid excuse: it has never received funding to achieve this goal.
Now, however, there is some hope of finding deadly asteroids. The National Science Foundation has supported the Large Synoptic Survey Telescope (LSST) in Chile, and NASA is considering funding NEOCam, a space-based infrared telescope that would specialize in identifying potentially dangerous asteroids. But scientists weren’t entirely sure how these two instruments would perform in a joint hunt for large asteroids.
A new pre-print on arXiv offers some clarity, and the answer seems to be that the ground-based and space-based approaches will complement each other nicely. According to a new simulation of near-Earth threats and the capabilities of these two instruments, neither the ground-based telescope nor NEOCam would come close to finding all the potential threats on their own. Combined, however, they were expected to find just over 90 percent of threats.
“The benefits of using both NEOCam and LSST are numerous,” the authors write. They will observe complementary regions of space, and because LSST will use optical light – while NEOCam observes in the infrared – they will get better size, albedo and color information about these asteroids and a better understanding of their composition, an important determining factor. factor for the overall threat of a large asteroid.
The study, which has been accepted for publication in the Astronomical magazine, was led by Tommy Grav, a planetary scientist at the Planetary Science Institute. He and another co-author, Amy Mainzer, are principal investigators on the NEOCam mission, which NASA considers one of five finalists for full funding as part of its Discovery program.