James Webb found Neptune's moon Nereid has an unusual icy surface, suggesting it formed alongside the planet instead of being captured later.

CAPE CANAVERAL, Fla. — Neptune’s far-flung moon Nereid may be the last of the plane t ’s original companions that managed to survive a cosmic crash, scientists reported Wednesday. Sixteen known moons ...

The Hubble Space Telescope has peered at Uranus, left, and Neptune to study the so-called "ice giant" planets, but little is known about their interior composition. Credit: NASA / ESA / M. Showalter / ...

Deep inside planets like Uranus and Neptune, scientists may have uncovered a bizarre new state of matter where atoms behave in unexpected ways. Advanced simulations suggest that carbon and hydrogen, ...

On the night of July 15, a striking conjunction of the moon, Saturn, and Neptune will unfold in the eastern sky, offering stargazers across the United States a chance to witness three celestial bodies ...