Planet Nine is out there, and astronomers are determined to find it, according to a new statement by NASA.
Neptune, the other blue planet, is the eighth planet in our solar system. Neptune is an ice giant.
Since NASA's Cassini spacecraft has ended its epic 13-year stint at Saturn, here's a look at some other missions en route to new destinations or slated to launch in the next few years.
Look up tonight (Sept. 6) to see the Full Corn Moon glowing in the sky. If you have binoculars or a telescope, you can also see the planet Neptune glowing faintly nearby.
In honor of NASA's Voyager 1 probe's 40th anniversary today (Aug. 5), William Shatner helped send a special message to the distant spacecraft, selected by popular vote.
"Diamond rain" that may shower through the layers of Neptune and Uranus has been created in a laboratory for the first time, according to a new study.
Voyager project scientist Ed Stone discusses the greatest achievements of the epic mission, which lifted off 40 years ago today (Aug. 20).
NASA's epic Voyager mission began on Aug. 20, 1977, with the launch of the Voyager 2 probe. Space.com has selected 40 great Voyager photos to celebrate the mission's 40th anniversary.
For the first time, scientists have seen bands of clouds drifting across the skies of failed stars known as brown dwarfs.
A nearly Earth-size storm system was spotted near Neptune's equator, surprising scientists because no bright clouds have ever been seen in that location.
A new Neptune study shows that you don't need to be a professional to do science; amateurs make contributions, too.
New NASA mission ideas would investigate the gassy environments of Uranus and Neptune, two planets on the edge of the solar system that spacecraft have visited only once.
Planets and other celestial bodies can take many types of paths through space. Learn all about the different kinds of orbits in the sixth episode of "We Don't Planet."
The Kepler space telescope, NASA's dedicated exoplanet hunter, has provided a new look at a world close to home: the gas giant Neptune.
The rings of Saturn, Neptune and Uranus are composed of pieces of Pluto-like dwarf planets that strayed too close to the giant worlds long ago, a new study suggests.