A newly discovered warp in the outer Solar System may have been created by a small, rocky world, much closer to the Sun than ...

The existence of "Planet Nine," a hypothetical planet in the outer solar system, is supported by indirect evidence such as the unusual clustering of orbits of extreme trans-Neptunian objects (ETNOs) ...

A new study suggests yet another theory for a possible extra planet in our solar system, likely of a size between Mercury and ...

There's a new object in the distant reaches of our solar system, and it might just offer clues to a long-standing cosmic mystery. Astronomers have cataloged a frozen minor planet called 2017 OF201, ...

When you buy through links on our articles, Future and its syndication partners may earn a commission. A composite image comparing the relative sizes of our solar system's known dwarf planets, ...

Astronomers are investigating a potential hidden planet, dubbed Planet Y, far beyond Neptune. Its gravitational pull is ...

Scientists are observing an Earth-like exoplanet that may contain water using NASA's James Webb Space Telescope, the space agency said in a news release. The exoplanet, known as TRAPPIST-1 e, orbits ...

This illustration shows an exoplanet orbiting around two brown dwarfs –– objects bigger than gas-giant planets but too small to be proper stars. ESO/M. Kornmesser Astronomers have discovered a ...