Frigid and far-flung Neptune, our solar system's outermost planet, is adding to its reputation as an enigmatic world, with astronomers puzzled by a surprising drop in its atmospheric temperatures ...

In October 2017, NASA released a statement saying that Planet Nine may be 20 times further from the Sun than Neptune is, going so far as to say "it is now harder to imagine our solar system ...

Neptune is the fourth largest planet in the solar system, with a radius of 15,599.4 miles (24,622 kilometers) — the distance between its core and the surface.

Uranus (left) and Neptune photographed by Voyager 2. NASA/JPL. In our solar system, the two outermost planets of Uranus and Neptune are something of an oddity.

Oddball planet TOI-1231 b is a bit smaller than Neptune but has a substantial atmosphere, which gives it some interesting astronomical quirks. Skip to main content Menu ...

Previous studies, including work by Nesvorny, have suggested that the early solar system originally accommodated more giant planets than just Jupiter, Saturn, Uranus, and Neptune, a scenario that ...

Neptune is among the least explored of the solar system’s eight planets, with its great distance making it difficult to study from Earth. NASA’s Voyager 2 is the only spacecraft to have made a ...