In the far reaches of the solar system, beyond Neptune, there is a minor planet orbiting the sun in a sea of icy debris. Humans have known about the reddish, round object for more than a decade. Since ...

Active small bodies—including comets, active asteroids, icy minor planets, and transitional objects—occupy a unique position in planetary science. As ...

Mike Brown is convinced that beyond Neptune, at the far reaches of our solar system, there's an unseen giant planet. "This is the 5th largest planet in our solar system, lurking out there, waiting to ...

On May 21, the International Astronomical Union's Minor Planet Center announced the discovery of 2017 OF 201, which, because of its distance beyond Neptune, is classified as a trans-Neptunian object ...

While the James Webb Space Telescope looks for the most distant galaxies ever seen, astronomers have discovered something new in our very own solar system. Researchers from the U.S. and Canada have ...