NASA's new chief wants to reinstate Pluto as a planet. And scientists are on board – as long as you're also okay with having ...

Researchers estimate that the number of captured free-floating planets in the outer solar system with mass strictly greater than that of Mars is ∼1.2 and that the number of such planets with a strict ...

Ever since NASA’s New Horizons spacecraft flew by Pluto last year, evidence has been mounting that the dwarf planet may have a liquid ocean beneath its icy shell. Now, by modeling the impact dynamics ...

Two decades ago, the International Astronomical Union—which defines and names celestial bodies—redefined the criteria for being a planet, putting Pluto into the new category of dwarf planet ...

The mystery of how Pluto got a giant heart-shaped feature on its surface has finally been solved by an international team of astrophysicists. The team is the first to successfully reproduce the ...

NASA Administrator Jared Isaacman wants to put an end to a decades-long debate among scientists. Is Pluto a planet or not? Isaacman says it should be — but it hasn’t been one for 20 years. That’s ...