IGPP Seminar Series

Probing Asteroid Physics, Solar Physics, and Fundamental Physics with Radar Astrometry

by Jean-Luc Margot
Earth & Space Sciences, UCLA


I will describe the first phase of a long-term program designed to obtain and interpret high-precision radar range measurements of a number of near-Earth objects (NEOs) that have trajectories reaching deep inside the gravitational well of the Sun. Measurements in this extreme dynamical regime simultaneously probe asteroid physical properties, solar physics, and fundamental physics. The objectives of the program are three-fold: 1) to measure Yarkosvky drift rates, which depend on asteroid masses and thermal properties, 2) to provide a purely dynamical measurement of the oblateness of the Sun, 3) to refine solar system tests of general relativity. Four NEOs have been observed at Arecibo on at least two apparitions since 2000, with typical uncertainties of a few hundred meters. Data obtained to date are not sufficient to allow for a reliable estimation of solve-for parameters, as expected, but the first meaningful measurements are anticipated in the next three years.
Tuesday, 19 May 2009
3853 Slichter Hall
Refreshments at 3:45 PM
Lecture at 4:00 PM