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Дата изменения: Tue Dec 14 13:44:25 1999 Дата индексирования: Tue Oct 2 04:01:59 2012 Кодировка: Поисковые слова: южная атлантическая аопнбмйс |
Dr John Chambers has made detailed computer simulations of the origin and formation of the Earth and the inner planets. These build upon earlier work by Chambers and George Wetherill, of the Carnegie Institution of Washington, whose computer calculations had predicted that planets would tend to have elliptical orbits rather than the almost-circular ones we see in the Solar System. If true, this would have profound implications for the habitability of extra-solar planets, as elliptical orbits induce large swings in climate. The new simulations have a more interesting range of outcomes. Several calculations yielded Earth-like planets moving on almost circular orbits, which allows them to have stable climates. However, a significant fraction of planets are likely to have highly elliptical orbits, so that they are unlikely to be able to support life.
A new algorithm has also been developed for solving the N-body problem -- a tough computational task necessary to understand many aspects of astrophysics. In particular, the new method has considerably speeded up computer simulations of planet formation, making it possible to get a better understanding of how the Earth, the Moon, the planets, and the asteroids formed.
Michael Brown (a final-year student at Trinity College, Dublin) extended earlier work on the stability of planetary systems. He finds that many systems become unstable if one waits long enough. This instability is especially likely if the planets have a wide range of masses, due to the occurrence of chaotic motion generated by repeated configurations of the planets.
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