Near-Earth Asteroid Discovery and Globally Optimized Follow-Up

Tuesday, 20 December 2022 7 a.m. — 8 a.m. MST

AURA Lecture Hall

NOIRLab South Colloquia
Eric J. Christensen (The University of Arizona Lunar and Planetary Laboratory)

The Catalina Sky Survey (CSS) has been funded by NASA for over two decades to detect and track Near-Earth Objects (NEOs): asteroids and comets that come to perihelion closer than 1.3 AU. Over 30,500 NEOs have been cataloged, with CSS discovering nearly half of these. The current focus of CSS is to continue the search for larger asteroids deemed a priority by NASA, while also maintaining sensitivity to small, very nearby NEOs. This dual focus has led to discoveries such as 2020 CD3, a temporarily bound “mini-moon”, and small imminent Earth impactors, such as the recent discovery of 2022 WJ1 which impacted over Ontario, Canada only about 4 hours after it was first detected by CSS. Follow-up is an integral part of NEO discovery and to ensure the orbits of NEOs are well-known enough to predict future impacts, and to enable targeted characterization observations of interesting NEOs. CSS coordinates NEO survey and follow-up operations across multiple telescopes, ranging from full-time use of 0.7 – 1.5-m telescopes, to occasional competitive access to large telescopes including Gemini and the Large Binocular Telescope for the highest priority objects. To help with follow-up coordination and target selection, CSS developed and maintains a public NEO target broker called NEOfixer. NEOfixer creates telescope-specific lists of targets, ranking priority according to each object’s importance, along with the cost, benefit, and urgency of obtaining additional observations. NEOfixer is in widespread use in the NEO community, serving curated target lists to nearly 100 observatories.