The Life and Death of Planet Earth

The earth is a blue planet, pulsing with oxygen, carbon and life. But it won't last. Four, five, maybe six billion years from now, the sun will be a cool star and the earth a dusty husk. How and why will this happen?

When the sun cools, life, as rare as it is in the universe, will be gone from the earth. Planets live and die, as with all life, and we should enjoy it while we can. Geologist Peter Ward and astronomer Donald Brownlee are using the evolving science of astrobiology to put life on earth in perspective.

Peter Ward is a professor of earth and space sciences at the University of Washington and co-author of "The Life and Death of Planet Earth," along with Donald Brownlee, professor of astronomy.