Comets - Why?
- Introduction
- Comets
- Asteroids
- Meteorites
- Meteor Showers
- Rock Types
- Identification
- Origins
- Destruction
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Out in the frozen depths of the Kuiper Belt and Oort Cloud, the Sun’s radiation and gravitational grasp is diminished. Comets are vulnerable to other influences such as the relatively close passage (perhaps by a light year or so) of another star. To give some indication of how close other stars can get, the red dwarf star Gliese 710 will get to within 70,000 astronomical units, or ten trillion km – that’s actually inside the Oort Cloud, as far as we can tell – in around 1.4 million years time, before merrily going on its way. Its gravity will disrupt the orbits of millions of comets, slinging many of them our direction. The vast majority will pass harmlessly through the Solar System, although it is feasible that some may collide with Earth or other planets, much like when Comet Shoemaker-Levy 9 collided with Jupiter in 1994. It is these perturbations that can cause comets to wind up on trajectories that bring them into the inner Solar System and link their fates inextricably with ours.
Next Chapter: Asteroids
