Is there a distance at which a satellite will orbit a body indefinitely? Is this distance a universal constant? [more inside]
posted by doublehappy on Oct 16, 2009 - 28 answers

I'm working on a computer simulation of the solar system, but I need data on the positions and velocities on planets and their moons. (more inside) [more inside]
posted by deansfurniture5 on Mar 17, 2008 - 5 answers

Given our current state of technology and the world's nuclear armaments, I ask the question that the world needs an answer to: Could we destroy Mars? [more inside]
posted by TwelveTwo on Dec 24, 2005 - 41 answers

How would I determine sunlight levels for the planets in the outer solar system? [more inside]
posted by nightengine on Aug 26, 2005 - 8 answers

I want to buy my son, who is turning six, a telescope for his birthday. I don't want to spend a fortune, but one site I looked at for advice said anything less than $300 is a piece of junk. Anyone have any advice (including specific models) on one I can by this budding astronomer for $100 or less?
posted by alexg23 on Jul 25, 2005 - 22 answers