The Mission Accessible Near Earth Object Survey (MANOS): Spectrophotometric Characterization of Small NEOs

The Mission Accessible Near Earth Object Survey (MANOS) Spectrophotometric Characterization of Small NEOs The Mission Accessible Near Earth Object Survey (MANOS) was designed to characterize sub-km, low delta-v, newly discovered near-Earth objects (NEOs). A subset of MANOS includes collecting color photometry in the Sloan Digital Sky Survey (SDSS) filter set, which can be used to produce rough taxonomic assignments for our targets. Such information is critical for (1) understanding how the Solar System formed as NEOs are remnants from the epoch of planet formation, (2) the interpretation of meteorites as NEOs are their primary producers, and (3), resource extraction missions in space; which are soon to become reality with future manned missions expected to extend beyond low earth orbit. MANOS utilizes 4-m (Lowell Observatory's Discovery Channel Telescope, SOAR) and 8-m (Gemini North and South) telescopes which enables traditional spectroscopy down to an apparent visual magnitude of 19.5 and 20.5 respectively. The NEOs observed by MANOS have an average absolute magnitude of H > 21, corresponding to objects with a mean diameter in the 100m range. These relatively small targets are most often discovered near peak brightness around V 20-21 mag, with follow up observations during subsequent apparitions being infeasible as targets return on average 100 times fainter (Galache et al. 2015). By performing coarse spectrophotometry, we are offered a unique opportunity to characterize particularly small NEOs, a currently under sampled portion of the NEO population. Our comprehensive data set contains spectrophotometric results for over 100 targets. These data will be compared to the Sloan Digital Sky Survey Moving Object Catalog, which contains a similar size sample of km-scale NEOs. It is understood that while more than 80% of meteorites have origins traced to S-type asteroids (Harvey & Cassidy 1989), only 60% of the large NEOs are designated as such (Binzel et al. 2018). Our sample bridges the gap between meteorites and large NEOs, and thus can provide insight into this discrepancy. This work is supported by the NASA NEOO program, grant number NNX17AH06G.