Radar observations of asteroids and comets
Abstract
Radar observations of asteroids and comets provide information about these objects' sizes, shapes, spin vectors, decimeter-scale morphology, topographic relief, regolith porosity, and metal concentration. On average, small, near-earth asteroids are rougher at decimeter scales than comets or mainbelt asteroids. Asteroid 2 Pallas is smoother than the moon at decimeter scales but much rougher than the moon at some much larger scale(s). There is at least a five-fold variation in the radar albedos of main-belt asteroids, implying substantial variation in these objects' surface porosities or metal concentrations. The highest albedo estimate, for 16 Psyche, is consistent with a metal concentration near unity and lunar porosities. The radar polarization signature of the near-earth object 2101 Adonis is anomalous, resembling that of Jupiter's satellite Callisto more than that of any other radar-detected planetary target. The echo spectra of comet IRAS-Araki-Alcock reveal an irregular, ≡7-km sized nucleus and an associated debris swarm, at least 103 times larger than the nucleus and comprised of particles at least a centimeter in size.
- Publication:
-
Publications of the Astronomical Society of the Pacific
- Pub Date:
- October 1985
- DOI:
- 10.1086/131619
- Bibcode:
- 1985PASP...97..877O
- Keywords:
-
- Asteroids;
- Comets;
- Radar Astronomy;
- Radar Detection;
- Apollo Asteroids;
- Iras-Araki-Alcock Comet;
- Power Spectra;
- Radar Echoes;
- Toro Asteroid;
- Astronomy