Strongly differentiated material in high-inclination and retrograde orbits
Abstract
Much of our present understanding of the origin and evolution of the solar system has come from the study of meteorites which represent the oldest material available for analysis. The currently proposed sources for the meteoroids, especially the highly differentiated ones (main belt asteroids, Apollo asteroids, defunct short-period comet nuclei), are all in short-period, direct orbits and give Earth-atmosphere entry velocities of about 40 km/sec or less. We now have direct evidence of the existence of strongly differentiated material in comet-type orbits. This evidence is a set of meteor spectrograms of essentially iron-free material entering the Earth's atmosphere at high velocities (V >40 km/sec) from high4nclination and retrograde orbits.
- Publication:
-
The Astronomical Journal
- Pub Date:
- February 1974
- DOI:
- 10.1086/111547
- Bibcode:
- 1974AJ.....79..333H