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 ...

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 ...

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 ...

For centuries our solar system was the only planetary system known to humans. We had no proof other worlds existed beyond those in our own cosmic backyard, and we imagined that if other planetary ...