Add Yahoo as a preferred source to see more of our stories on Google. silhouette of a person looking up at the night sky Our Solar System orbits the galactic center at an estimated 792,000 kilometers ...

A recent resurgence of interest in a bold cosmological theory has reignited debate about the nature of dark matter, the Big Bang, and the possible existence of a mirror universe. Originally proposed ...

Whether or not galaxies merge depends on how strong the gravitational attraction is between the galaxies and whether the universe's expansion is more powerful than gravity. Gravity affects everything ...

If there is an absolute law in the universe, it’s that nothing can travel faster than the speed of light. For science-fiction enthusiasts, that’s a bit depressing. Space is big, and while the speed of ...