Our solar system now, once again, officially consists of only eight planets. Although largely debunked, speculation continued ...

Click to share on X (Opens in new window) Click to share on LinkedIn (Opens in new window) Click to share on Facebook (Opens in new window) Click to share on Reddit (Opens in new window) Click to ...

(Correction: An earlier version of this story misstated how far Pluto is from the sun. The correct number is 3.7 billion miles.) What was discovered in Flagstaff, Arizona, and killed off in Prague? If ...

A spacecraft operated by the European Space Agency and the Japan Aerospace Exploration Agency has made its final flyby of Mercury, as scientists now work to guide BepiColombo into the planet’s orbit.

Astronomers from Princeton and other institutions have discovered the smallest planet found outside of our solar system using a technique that researchers believe will uncover others that potentially ...

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

A recently observed object was found orbiting near the Earth. The quasi-moon is expected to accompany our planet in a similar ...

SEATTLE – NASA has discovered the smallest planet ever seen beyond our solar system – a rocky world just 1.4 times larger than Earth – using its planet-hunting Kepler observatory. The planet, called ...