Dr. Paul Chodas
NASA NEO Program Office
Jet Propulsion Laboratory
Finding and Tracking Near-Earth Objects, and Maybe Even Capturing One
On February 15, 2013, a much anticipated close passage of a small asteroid within the ring of geosynchronous satellites was just about to occur when another asteroid, half the size of the first, stole the spotlight by impacting into the Earth's atmosphere high above Chelyabinsk, Russia, producing a half-megaton explosion that reportedly injured more than a thousand people. The predicted close passage of a 40-meter asteroid, calculated to be a a once-in-40-year event, was upstaged on the same day by an actual Earth impact of a previously unseen 20-meter asteroid, something which happens only about once per century. The Chelyabinsk fireball was in fact the largest asteroid impact event since the Tunguska explosion over Siberia in 1908. NASA's Near-Earth Object (NEO) Observations Program is working to ensure that larger and more hazardous asteroids do not hit our planet without warning; the program is responsible for 98% of NEO discoveries since it began in 1998. Over 90% of the civilization-killer NEOs larger than 1 kilometer in size have now been catalogued and confirmed to be on non-impacting trajectories. The NEO program is now focused on discovering smaller objects, down to 140 meters in size, which could still cause widespread devastation on impact. This seminar will discuss the process of searching for asteroids, tracking them and predicting potential Earth impacts, and will examine possible methods for diverting on object on a collision course with Earth. The talk will also cover NASA's proposed Asteroid Redirect Mission, in which a small 5-10 meter asteroid could be captured and guided into orbit about the Moon, where it could be visited by astronauts on one of the early Orion/Space Launch System missions.
UW grad Paul Chodas is a senior scientist at the Jet Propulsion Laboratory in Pasadena, California, where he has computed trajectories of asteroids and comets for over 30 years. A native of London, Ontario, Paul received a Bachelor's degree in Applied Mathematics from the University of Waterloo, followed by an MASc and PhD in aerospace engineering from the University of Toronto. Paul is the architect for much of JPL's small body software that determines orbits and orbit uncertainties for asteroids and comets, plots trajectories, computes impact probabilities and predicts impact times and locations. He has been a key member of NASA's NEO Program Office since its inception. In 1999 he coined the term "keyhole" to describe a potential gateway that leads from an Earth close approach to a later impact. Currently, he leads the effort for finding and characterizing candidate targets for NASA's proposed Asteroid Redirect Mission.
Wine and cheese reception to follow in MC 2018A.