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Contamination of the asteroid belt by primordial trans-Neptunian objects.
- Source :
-
Nature . 7/16/2009, Vol. 460 Issue 7253, p364-366. 3p. 2 Graphs. - Publication Year :
- 2009
-
Abstract
- The main asteroid belt, which inhabits a relatively narrow annulus ∼2.1–3.3 au from the Sun, contains a surprising diversity of objects ranging from primitive ice–rock mixtures to igneous rocks. The standard model used to explain this assumes that most asteroids formed in situ from a primordial disk that experienced radical chemical changes within this zone. Here we show that the violent dynamical evolution of the giant-planet orbits required by the so-called Nice model leads to the insertion of primitive trans-Neptunian objects into the outer belt. This result implies that the observed diversity of the asteroid belt is not a direct reflection of the intrinsic compositional variation of the proto-planetary disk. The dark captured bodies, composed of organic-rich materials, would have been more susceptible to collisional evolution than typical main-belt asteroids. Their weak nature makes them a prodigious source of micrometeorites—sufficient to explain why most are primitive in composition and are isotopically different from most macroscopic meteorites. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00280836
- Volume :
- 460
- Issue :
- 7253
- Database :
- Academic Search Index
- Journal :
- Nature
- Publication Type :
- Academic Journal
- Accession number :
- 43217719
- Full Text :
- https://doi.org/10.1038/nature08094