OT: Astronomy Picture of the Day

[PvK]

From http://antwrp.gsfc.nasa.gov/apod/ap060730.html ,

"The origin of the Valles Marineris remains unknown, although a leading hypothesis holds that it started as a crack billions of years ago as the planet cooled."

Planetary orbits seem to be more stable than stars themselves.

I don't think planets are likely burped out of stars, but are probably formed back when the star itself was formed.

However, the star's behavior can change, and things can smash into planets and change their environments (or, their human-stupid inhabitants can destroy their environments themselves...).

PvK