It's been one Neptunian year—or about 165 Earth years—since astronomers first observed the most distant planet from the sun.

An artist's interpretation of what Planet Nine might look like. As the search for "Planet Nine" in the outer solar system continues, new research suggests there may be an Earth twin buried deep within ...

Editor’s note: Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on fascinating discoveries, scientific advancements and more. Space-based observatories such as the ...

Using ESO's Very Large Telescope (VLT), astronomers have observed a large dark spot in Neptune's atmosphere, with an unexpected smaller bright spot adjacent to it. This is the first time a dark spot ...

Neptune and Uranus are the seventh and eighth planets from the sun, and as such share a lot of the same characteristics. Though they are different colors (Neptune is bluer than Uranus' cyan hue) and ...

Of all the potential super-Earths—terrestrial exoplanets more massive than Earth—out there, an exoplanet orbiting a star only 40 light-years away from us in the constellation Cetus might be the most ...

Alfredo has a PhD in Astrophysics and a Master's in Quantum Fields and Fundamental Forces from Imperial College London.View full profile Alfredo has a PhD in Astrophysics and a Master's in Quantum ...

Far-flung science fiction often depicts humanity as an interplanetary (or even interstellar) species, but there’s a lot of technological advancement that needs to happen to move us from Earthbound ...

While the most famous planetary spot in the solar system would have to be Jupiter’s Great Red Spot, an epic storm 10,000 miles wide that has been raging for hundreds of years, other planets are known ...

A strange dark spot on Neptune has been observed from Earth for the first time, offering fresh clues into how these marks form. In 1989, NASA’s Voyager 2 space probe detected a shadowy region on ...