The Yarkovsky Effect on Near-Earth Asteroid (101955) Bennu, Target of the OSIRIS-Rex Mission: A review of the literature, by Robert Melikyan
Abstract
The Yarkovsky effect is a nongravitational phenomenon resulting from anisotropic thermal emissions of rotating asteroids. It took more than 100 years between theory and detection (first seen in asteroid 2489 Golevka in 2003). Now, the near-earth asteroid 101955 Bennu has shown a mean semi-major axis drift da/dt = 284 +/- 1.5 m/year due to the Yarkovsky effect. Non-gravitational drift can greatly affect the probability of asteroid impact with earth making accurate modeling of the Yarkovsky effect a high priority for NASA. The OSIRIS-REx mission is currently delivering a satellite into orbit around Bennu. Amongst the mission objectives is the measurement of the asteroid's thermophysical properties that contribute to the Yarkovsky effect, such as the thermal conductivity of the surface. This is important because the observations necessary to measure thermophysical properties from Earth are much more difficult than from a spacecraft platform. Another difficulty is that the highly elliptical orbits of most near-earth asteroids can greatly increase error. Bennu, with the ``eyes'' of the OSIRIS-REx mission, acts as the perfect aid for observing and understanding the characteristics of this important non-gravitational effect that makes asteroid orbits so hard to predict into the future.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- 2019
- Bibcode:
- 2019APS..MARG70039M