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From interstellar dust to comets
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Greenberg, J. M. |
| Copyright Year | 1989 |
| Description | The bulk and microstructure of comet nuclei are derived from the morphological structure and chemical composition of submicron sized interstellar dust grains which have undergone cold aggregation in the pre-solar nebula. The evolutionary picture of dust which is emerging is a cyclic one in which the particles, before being destroyed or going into solar system bodies, find themselves during their 5 billion year lifetime alternately in diffuse clouds and in molecular clouds. A small silicate core captured within a molecular cloud accretes various ices and gradually builds up an inner mantle of organic refractory material which has been produced by photoprocessing of the volatile ices. Clumps of grains form, and then clumps of clumps, and so on, until finally we reach the size of the comet nucleus. |
| File Size | 186335 |
| Page Count | 2 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19900007304 |
| Archival Resource Key | ark:/13960/t5r837q44 |
| Language | English |
| Publisher Date | 1989-01-01 |
| Access Restriction | Open |
| Subject Keyword | Astrophysics Organic Materials Molecular Clouds Ice Silicates Microparticles Refractory Materials Cosmic Dust Comet Nuclei Morphology Clumps Chemical Composition Microstructure Nebulae Interstellar Matter Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
