Astronomers have uncovered a massive new trans-Neptunian object, 2017 OF201, lurking at the edge of our solar system. With an ...

A new trans-Neptunian object, 2017 OF201, has been found with a vast orbit and potential dwarf planet size. The finding hints ...

The solar system lost its ninth planet back when Pluto was demoted to a dwarf planet, but research might indicate that there ...

From the scorching surface of Mercury to the icy edges of Neptune, our planetary neighborhood is full of wonders. The order of the planets isn’t just trivia—it tells a story about temperature, ...

The origin of the differing tilts in the orbits of the planets in our solar system may have been revealed through the ...

A quick guide to planets, including the eight in our solar system, how they form, and how many could be in the universe.

Astronomers have directly spotted a rare young planet, WISPIT 2b, still forming within the gap of a dusty ringed disk around ...

Astronomer and Pluto mission leader S. Alan Stern explores how the field has transformed during his decades-long career.

Astronomers using a pair of planet-hunting satellites discovered a solar system with at least six planets rotating around a star in perfect sync with each other.

In the solar system’s early years, the still-forming giant planets sidestepped, did a do-si-do and then swung one of their partners away from the sun’s gravitational grasp. Things settled, and ...

Astronomy has come a long way in the 401 years since Galileo turned his first primitive telescope to the sky, so it's no surprise we see a very different solar system than the field's earliest ...

Two planets orbit the poles while another revolves around the star’s equator, suggesting a mysterious, undetected force.