Far beyond the bright planets, in the dim outskirts of the Solar System, astronomers keep stumbling on objects that refuse to ...

A passing star, or a stellar flyby, with the potential to pull Neptune out of its orbit by just 0.1%, could mean catastrophe for the entire solar system. But don’t worry — it won’t happen in our ...

While Mercury is the innermost planet in the Solar System, on average it spends more time closer to Earth than Venus does.

The eighth and most distant planet from the sun, Neptune, reaches opposition with the sun on Sept.23, when it will be in its best position for viewing for the year. Neptune is too faint to see with ...

What can sub-Neptunes, exoplanets whose sizes are between Earth and Neptune, and which are between the known for their water-rich compositions, teach astronomers about both where and how to find life ...

What happens when a planet contains immense quantities of water but is far too hot for that water to remain liquid?

Models for the interior structures of the ice-giant planets Uranus and Neptune have two distinct, intermediate layers: an upper, water-rich convecting layer where disorganized magnetic fields are ...