Pluto is a bit of a loner. The dwarf planet is no longer considered a regular planet; it does not orbit on the same plane as the solar system's eight planets; and its orbit is both highly elliptical ...

"'Oumuamua is in a different category of object. It's much harder to find, but there are a lot more of them." The first interstellar object to visit the solar system may have been a fragment of an icy ...