Does our Solar System have 9 planets or only 8? Astronomers have gone back and forth on that a lot, with Pluto now being classified as a dwarf planet. However, out beyond Neptune there could be ...

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

"With an orbital period of 570 days, it is a relatively cold gas giant planet," said Guðmundur Stefánsson of the University ...

Pluto isn't alone—it's part of the Kuiper Belt with possibly hundreds of other planet-sized objects. Because Pluto hasn't ...

Gaia-4b is considered a super-Jupiter planet, a relatively cold gas giant, orbiting its star over 570 Earth-days. That star ...

"Our Sun (Sol) is marked by a black hexagon, and its orbital path is indicated by a grey solid line (top row only). Alpha Centauri's location and path are shown by a yellow star and a solid blue line ...

Take advantage of a special 6-7 planet alignment from Earth's perspective. Planets 'line up' in the skies over California in ...

Our solar system contains planets, dwarf planets, asteroids and comets — but only one world is known to harbor life. Scientists have long debated whether Earth is truly unique. Perhaps our planet just ...

Oumuamua and Comet Borisov in 2017 and 2019, respectively, created a surge of interest. What were they? Where did they come ...

In August 2006, the International Astronomical Union made the controversial, but correct, decision to demote Pluto from its ...