Imagine a world where the very air we breathe is slowly, naturally, beginning to thin out. While our planet's vibrant ...

Arsia Mons, which dwarfs Earth's tallest volcanoes, and its two neighboring volcanoes are often surrounded by water ice ...

June’s full moon, known as a “strawberry moon,” may appear reddish because of its low position on the Southern Horizon.

A NASA orbiter has captured a stunning image of a giant volcano on Mars. The panorama, captured on May 2 by NASA’s Mars ...

U.S. astronomers hunting for "Planet Nine" have instead stumbled on what appears to be a new dwarf planet in the solar system ...

It's an evocative idea that has long bedeviled scientists: a huge and mysterious planet is lurking in the darkness at the ...

While orbiting Earth aboard SpaceX's Dragon spacecraft, McClain captured the aurora glowing like a soft, neon-green ribbon ...