Thursday, February 4, 2010
Dying Stars Eat Comets For Their Last Supper
From New Scientist:
WHEN the sun dies, it's not just Earth that will be doomed - the destruction will reach as far as the comets in the outer solar system. That's according to a new explanation of the behaviour of planetary nebulae - bubbles of gas sloughed off by dying stars (pictured).
There are two methods for calculating the abundance of elements in planetary nebulae: looking at light emitted when electrons and ionised atoms recombine, or looking at the energy emitted by atoms excited by collisions. Yet they yield very different results, a discrepancy that has baffled astronomers for decades.
Read more ....