The small world was found during a search for the hypothetical Planet Nine, and astronomers say the next time it will reach ...

As it orbits the sun once every 25,000 years, the celestial body 2017 OF201 travels beyond the Kuiper Belt into a region ...

Simulations show that the stars’ tug could send Mercury, Venus or Mars crashing into Earth — or let Jupiter eject our world from the solar system.

China’s Tianwen-2 mission has launched to explore an asteroid that may be a piece of the moon, as well as an active asteroid ...

Discovery of a possible dwarf planet suggests our cosmic backyard holds many more secrets to uncover It is an evocative idea ...

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

Lunar exploration is entering a new era. Long after the Apollo missions, a renewed international interest comes with ...

There's no shortage of round celestial objects in our universe. Planets, moons and stars all exhibit lovely spherical shapes.

Only a tiny sliver of the Universe’s light can be seen by human eyes. But today we’re catching glimpses of the invisible ...