The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

Planet demographics reveal a puzzling lack of worlds in a certain size range throughout the galaxy F or centuries our solar system was the only planetary system known to humans. We had no proof other ...

Feb. 18 marks the 95th anniversary of the discovery of our outermost planet-not-planet. Here's what to know about the short ...

A planet-size object that possibly once visited the solar system may have permanently changed our cosmic neighborhood by warping the orbits of the four outer planets, a new study suggests.

A star system has been discovered to be moving at an estimated 1.2 million miles per hour, making it possibly the fastest moving solar system in our galaxy.

Pluto may not be a planet any more, but you still have a chance to see the distant dwarf planet at one of Michigan's observatories.

It is the fastest wind ever measured in a jetstream that goes around a planet. In comparison, the fastest wind ever measured in the Solar System was found on Neptune, moving at 'only' 0.5 km per ...

The James Webb Space Telescope has given astronomers groundbreaking insight into a new type of planet described as unlike anything in our solar system ... a collaborative project between NASA ...