A rare discovery beyond Neptune is forcing scientists to rethink early solar system dynamics and the forces that shaped distant worlds.

Astronomers are closing in on one of the most tantalizing possibilities in planetary science, evidence that a previously unknown world may be lurking in the outer reaches of the solar system. The ...

A pellet of plutonium 238, illuminated by the glow of its own radioactivity. NASA and other space agencies use this material in radioisotope power sources for interplanetary missions to the solar ...

Scientists say studying objects like Ammonite, despite their immense distance, offers valuable insight into the solar system's formation and early evolution.

In 2015, a NASA spacecraft snapped spectacular photographs of Pluto, forever changing humanity’s view of that world. On Tuesday that same probe, New Horizons, will provide a closeup of the farthest ...

After studying thousands of computer simulations of the solar system, researchers at Rice University and the Planetary Science Institute think there’s a 40% chance an elusive “Planet Nine” or “Planet ...

The outer reaches of our Solar System continue to reveal a complex dynamical environment where the interplay of gravitational forces shapes the orbits of a myriad of distant bodies. Research in this ...

On January 14, 2005, the Huygens probe landed on Saturn’s largest moon, Titan. Huygens remains the first and only landing in any location in the outer solar system, the furthest distance from Earth a ...