Astrophysical Journal

Planet X myth debunked

It was an elusive planet that for 200 years appeared to explain Uranus's wobbly orbit. And there was the sister sun theorized to be near our solar system that caused asteroids to swerve toward Earth.

Mar 16, 2014 3.8 / 5 (42) 61

Retrieving an asteroid

(Phys.org) —Asteroids (or comets) whose orbits bring them close to the earth's orbit are called near Earth objects. Some of them are old, dating from the origins of the solar system about four and one-half ...

Dec 27, 2013 4.9 / 5 (32) 60 | with audio podcast