Asteroid Research


Artist’s conception of the NEOWISE spacecraft. Image credit: NASA, JPL/Caltech.

I’m really into asteroids. I’m part of a team of scientists that uses the NEOWISE spacecraft to discover and study asteroids. NEOWISE is an infrared telescope that orbits the Earth, taking a photograph of outer space every 11 seconds. NEOWISE has seen over 158,000 asteroids, and has discovered over 30,000.

Asteroids are interesting to study because there’s a lot left to learn about them. Most asteroids haven’t been discovered yet. Out of the asteroids we have discovered, we only have measured sizes for about one in five. With the NEOWISE spacecraft, we can discover asteroids and measure how big and bright they are.

I am also part of the science team working on the proposal for a next-generation asteroid hunting spacecraft called NEOCam. NEOCam is one of five Discovery missions funded for further study by NASA. NEOCam would measure the sizes and brightnesses of millions of asteroids, and would be the largest infrared survey of comets.

NEOCam would also discover a tremendous number of asteroids, including hazardous asteroids. Right now, we have only discovered about 25% of asteroids large enough to cause regional destruction if they were to impact Earth (to learn more about how we know that percentage, see this interview). Although these asteroids are large compared to buildings and people, they are small astronomical objects and can be challenging to discover. NEOCam would find 66% of these objects 4 years after launch.

I’m also interested in various flavors of asteroid science. I use computer simulations of asteroid surfaces to measure asteroid thermal inertias, a process known as theromophysical modeling. Thermal inertia measurements can be linked to asteroid composition, can constrain the presence of surface regolith, and provide valuable information to spacecraft mission planners.

I have a Ph.D. in Geophysics and Space Physics from UCLA. My dissertation examined the non-gravitational forces that act on near-Earth asteroids. Understanding these forces can lead to better predictions of asteroid trajectories (something the dinosaurs could have used), and can also give insight into the evolution of our solar system.

Selected Publications:

C. R. Nugent et al., “Observed asteroid surface area in the thermal infrared,” The Astronomical Journal. Accepted.

C. R. Nugent et al., “NEOWISE Reactivation Mission Year Two: Asteroid Diameters and Albedos,” The Astrophysical Journal, vol. 152, p. 63, Sept. 2016

C. R. Nugent et al., “NEOWISE Reactivation Mission Year One: Preliminary Asteroid Diameters and Albedos,” The Astrophysical Journal, vol. 814, p. 117, Dec. 2015

C. R. Nugent et al., “The Yarkovsky Drift’s Influence on NEAs: Trends and Predictions with NEOWISE Measurements,” The Astronomical Journal, vol. 144, p. 75, Sept. 2012

C. R. Nugent et al., “Detection of Semimajor Axis Drifts in 54 Near-Earth Asteroids: New Measurements of the Yarkovsky Effect,” The Astronomical Journal, vol. 144, p. 60, Aug. 2012

For copies and a list of coauthored papers, see arXiv.


Artist’s conception of NEOCam. Image: JPL/Caltech.