Meet Earth’s closest known exo-relative, Kepler 78b. First discovered earlier this year, scientists today confirmed that it’s like Earth in more ways than one—Kepler 78b is rocky, about the same size, ...

Scientists have found a planet far out in the cosmos that's close in size and content to Earth -- an astronomical first. But this rocky world is so close to its sun that it's almost certainly too hot ...

Astronomers have discovered a world that is incredibly close to Earth-sized and may also be made of rock and iron, like our own planet. The only problem? It’s a scorched hellscape of molten lava that ...

CAPE CANAVERAL, Fla. — Scientists have found a planet way out in the cosmos that’s close in size and content to Earth — an astronomical first. But hold off on the travel plans. This rocky world is so ...

We didn’t even discover Pluto (the trans-Neptunian dwarf planet) until 1930. What’s more, we still don’t have a comprehensive map of our own solar system, so it’s no surprise that finding planets ...

Astronomers, always with their heads in the clouds, have discovered “the first Earth-size planet that seems to be made of the same mixture of rock and iron as Earth,” The New York Times reports.

A puzzling alien planet is the closest thing to an Earth twin in size and composition known beyond our solar system, though it's far too hot to support life, scientists say. The exoplanet Kepler-78b, ...

CAPE CANAVERAL, Florida (Reuters) – For the first time, scientists have found a planet beyond the solar system that not only is the same size as Earth, but has the same proportions of iron and rock, a ...

Kepler-78b is a planet that shouldn't exist. This scorching lava world circles its star every eight and a half hours at a distance of less than one million miles - one of the tightest known orbits.

Astronomers have discovered a planet that circles its star once every 8.5 hours, giving it one of the shortest orbital periods ever seen. It’s an exciting find, but not for the usual reasons. Much of ...

Astronomers have found that a planet discovered earlier this year is, in many ways, Earth’s twin. It’s the smallest exoplanets yet found for which we’ve been able to measure both its size and density.