Exoplanet hunters Christopher Watson and Annelies Mortier explain the long search for a 'twin Earth' capable of sustaining ...

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

We all need some space sometimes—but it's harder to find than you might think. How far into our universe do we have to go to ...

This is a question that human beings have wondered about for thousands of years. Here’s how the ancient Greek mathematician Metrodorus (400-350 B.C.) put it: A universe where Earth is “the only world, ...

The Copernican Principle, named in honor of Nicolaus Copernicus (who proposed the heliocentric model of the Universe), states ...

The Copernican Principle, named in honor of Nicolaus Copernicus (who proposed the heliocentric model of the universe), states ...

For all the talk about life across the cosmos, Earth remains the only confirmed example. That single data point makes your ...

A star about 600 light-years away is giving astronomers a front-row view to the environments in which rocky planets like Earth form around the most abundant stars in the universe. Called ISO-ChaI 147, ...

Stevenson 218 is the largest known star in the universe, located about 18,900 light-years away in the constellation of Scutum and far surpassing even the sun in size and brightness. So immense that it ...

Brown dwarfs, between about 13-80 Jupiter masses, will fuse deuterium+deuterium into helium-3 or tritium, remaining at the same approximate size as Jupiter but achieving much greater masses. If a star ...