Astronomers have discovered the first interstellar asteroid, nicknamed "Oumuamua" (Hawaiian for 'a messenger from afar arriving first'), in our solar system, and it was observed passing by Earth. The asteroid is described to be dark and reddish, without any gas or dust surrounding it. Initial observations have peg it at a quarter-mile long, and approximately 10-times longer than its width. Continue reading for another video and more information.
"Interstellar asteroids are thought to be rejects from other planetary systems. When our Solar System first formed, for instance, the giant planets tossed around all the smaller bits of material circulating around the Sun, some of which landed in the outer edges of the Solar System while others were ejected from our neighborhood completely. These outcasts then traveled through interstellar space, possibly passing by other stars. Conceivably, ejected material from other planetary systems must make their way to our Solar System once in a while, says Meech," according to The Verge.