Comets From Other Planetary Systems?

Most comets are thought to have originated great distances away, traveling to the inner solar system from the Oort Cloud. But new computer simulations show that many comets – including some famous ones – came from even farther: they may have been born in other solar systems. Many of the most well known comets, including Hale-Bopp (above), Halley, and, most recently, McNaught, may have formed around other stars and then were gravitationally captured by our Sun when it was still in its birth cluster. This new finding solves the mystery of how the Oort cloud formed and why it is so heavily populated with comets.

Comets are believed to be leftovers from the formation of the solar system. They are observed to come to the solar system from all directions, so astronomers have thought the comet's origin was from the Oort Cloud, a giant sphere surrounding the solar system. Some comets travel over 100,000 AU, in a huge orbit around the sun.

But comets may have formed around other stars in the cluster where the sun was born and been captured gravitationally by our sun.…

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