"If there are lots of black holes out there, some of them must surely pass through our backyard every now and then."

We now know that black holes occur frequently throughout the universe. One Sagittarius A* sits at the center of our galaxy, the Milky Way. In fact, according to NASA most galaxies of a similar size have monster black holes at their center. Sagittarius A* has approximately 4 million times more mass than the Sun.

Tiny black hole "bullets" left over from the Big Bang could be passing through Mars at speeds in excess of 7,000 times the speed of sound, causing the Red Planet to "wobble."

A new paper explores the idea of asteroid-sized objects that may be causing gravitational ripples in our cosmic neighborhood.