Check out scenes from Project Kuiper’s first mission, including during launch and inside Mission Control as the first ...

The Keck Observatory and NASA’s Hubble Space Telescope may have uncovered a "potential three-body system in the Kuiper Belt," ...

Astronomers have long speculated about an unseen planet lurking in the solar system's outer edge. This hypothetical world, ...

For years, astronomers have toyed with the idea that the Sun hides an extra planet so distant and dim that even the best ...