Planets travel alone in space, without a parent star. These wandering worlds, far from being rare, might even be extremely ...

Astronomers have finally weighed a wandering “rogue” planet, uncovering a Saturn-mass world flung into the galaxy after a dramatic planetary breakup.

Most of the planets we’ve identified are in orbit around stars and formed from the disks of gas and dust that surrounded the ...

Astronomers have detected a massive, lonely world drifting through the darkness without a star to call home. This ...

Astronomers poring over four years of data from NASA’s Kepler spacecraft have discovered a star that’s 11.2 billion years old and has at least five Earth-size planets. “We thus show that Earth-size ...

Researchers have confirmed the mass of a free-floating planet thanks to a lucky convergence of ground- and space-based ...

Is our Milky Way galaxy home to other planets the size of Earth? Are Earth-sized planets common or rare? NASA scientists seeking answers to those questions recently revealed their discovery. “We went ...

Using observations from both ground-based telescopes and space instruments, they were able to measure the planet's size and ...

Astronomers have discovered an Earth-size planet orbiting an ultracool red dwarf star similar in size to Jupiter. The red dwarf, located some 55 light-years away, is 100 times less bright than the sun ...

Beyond our solar system, countless alien worlds of lava, ice, water and noxious gas swirl through the cosmos. Here are some of the strangest exoplanets that scientists have discovered so far. When you ...

So far, humanity has yet to find its first "exomoon"—a moon orbiting a planet outside of the solar system. But that hasn't ...