The decades since scientists confirmed the first planet around another star have been rich in discovery, but it’s rare to see ...

Surprise, it's twins.

A rare planetary system has been discovered that mirrors the structure of our solar system, exoplanet formation, and gas ...

John Casani spent more than half a century turning speculative ideas about distant worlds into working spacecraft that could survive the trip. His quiet influence at NASA’s Jet Propulsion Laboratory ...

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 ...

The solar system has many more moons than the one we can see in the sky. But how many do we actually know about? And how many ...

An exoplanetary system about 116 light-years from Earth could flip the script on how planets form, according to researchers who discovered it using telescopes from NASA and the European Space Agency, ...

Planetary scientists have long debated where the material that formed Earth comes from. Despite its location in the inner ...

The standard story of the origin of our solar system has gone like this: 4.6 billion years ago, a giant cloud of dust hung frozen in space. Then the explosion of a nearby star caused part of that dust ...