A new study suggests yet another theory for a possible extra planet in our solar system, likely of a size between Mercury and ...

Astronomers have found new evidence, revealing the existence of an unseen and mysterious planet that could be hidden in the ...

There are 8 planets in our solar system. The planets orbit the Sun in elliptical trajectories, and they are all different in size, composition, temperature, and characteristics. The planets can be ...

Amir Siraj and team propose Planet Y, a possible unseen planet influencing Kuiper Belt object orbits. Vera C. Rubin ...

While Planet Y has been not yet been directly observed, unexpected inclinations found in the orbits of roughly 50 distant ...

If three’s a crowd, then six makes a chorus. That’s the case at least for a rare six-planet solar system whose discovery has wowed astronomers, even in an era when detecting planets around distant ...

In the 30 years since the discovery of 51 Pegasi b, more than 6,000 planets outside our Solar System have been catalogued. Two modern-day explorers explain how.

The workings of our solar system are roughly the same now as they have been for millions of years. Moons circle their planets, the planets circle the sun, the sun’s magnetic fields and sunspots wax ...

Our solar system is a smashing success. A new study suggests that from its earliest period—even before the last of its nebular gas had been consumed—Earth's solar system and its planets looked more ...

An interstellar comet passing through the solar system contains a surprising mix of chemicals, findings that could help researchers learn more about how planets and stars form elsewhere in the galaxy.

How Many Planets Are There in the Solar System? There are 8 planets in our solar system. The planets orbit the Sun in elliptical trajectories, and they are all different in size, composition, ...