Frost line (astrophysics)
 |
This article needs additional citations for verification. Please help improve this article by adding citations to reliable sources. Unsourced material may be challenged and removed. (December 2009) |
In astronomy or planetary science, the frost line, also known as the snow line or ice line, refers to a particular distance in the solar nebula from the central protosun where it is cool enough for hydrogen compounds such as water, ammonia, and methane to condense into solid ice grains. Depending on density, that temperature is estimated to be about 150K. The frost line of our solar system is around 2.7 AU, near the middle of the asteroid belt. The term is borrowed from the notion of "frost line" in soil science.
The lower temperature in the nebula beyond the frost line makes many more solid grains available for accretion into planetesimals and eventually planets. The frost line therefore separates terrestrial planets from jovian planets in the Solar system.[1]
However, gas giant planets have been found inside the frost line around several other stars (so-called hot Jupiters). They are thought to have formed outside the frost line, and later migrated inwards to their current positions.
[edit] Notes and references
- ^ Kaufmann, William J. (1987). Discovering the Universe. W.H. Freeman and Company. p. 94. ISBN 0-7167-1784-0.
[edit] See also
 |
This astronomy-related article is a stub. You can help Wikipedia by expanding it. |
