The star system V1298 Tau reveals that many planets begin as large, low-density worlds that slowly shrink and shed their ...

Mercury doesn't give up its secrets easily. The smallest planet in our solar system is also one of the most extreme—a sun-scorched, metal-rich world with a puzzling magnetic field and lavas unlike ...

A strange 200 million-year-old object with the mass of a planet has been discovered 20 light-years from Earth, outside our solar system. The "rogue," as it's referred to by researchers, is producing ...

The universe has a knack for throwing curveballs at astronomers. Just when scientists think they’ve got cosmic mechanics figured out, space reveals something so bizarre it rewrites the rulebook. These ...

Why it's weird: Other than being a possible member of the diamond-planet family, this world exhibits a few other strange characteristics, most notably its amazingly short orbital period—just 2.2 hours ...

A mysterious "rogue" planet has been observed gobbling six billion tonnes of gas and dust a second -- an unprecedented rate that blurs the line between planets and stars, astronomers said Thursday.