We live on a planet that seems motionless, yet Earth orbits the Sun at a dizzying speed, and our entire Solar System moves ...

Jupiter is already the biggest planet by far in our solar system, but new research suggests it was somehow once even larger than it is now. Twice as large, in fact. To put that into context, those ...

For the first time in years, astronomers are seriously talking about adding a new member to the solar system’s planetary ...

Some researchers suggest a different force shaped these orbits long ago—a wandering planet, one to two times Earth’s mass, that may have passed through the outer solar system in its early days. 2.

Studying the orbits of thousands of exoplanets shows that large planets tend to have elliptical orbits, while smaller planets tend to have more circular orbits. This split coincides with several other ...

"It is possible that a planet once existed in the solar system but was later ejected, causing the unusual orbits we see today." Astronomers have discovered a massive new solar system body located ...

Interstellar comet 3I/ATLAS got an accuracy boost thanks to a Mars orbiter, giving scientists insights and stronger planetary ...

The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have dubbed ...

Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory about the possibility of a giant ninth planet. The dwarf planet's existence ...