The newfound exoplanet, called Kepler-139f, is a gigantic world roughly twice the mass of Neptune and 35 times the mass of ...

A telescope has discovered a new world on the edge of the Milky Way – potentially confirming the ‘Planet X’ theory. Beyond ...

Researchers use the Subaru Telescope in Hawaii to find a small object on the outer edge of the Solar System. Nicknamed ...

Scientists have found an intriguing discrepancy in the way electrons behave in different calcium atoms. The difference between the observations and actual theoretical calculation is subtle; however, ...

Near-Earth asteroid Bennu has taught us a lot about the nature of asteroids and the history of our planet, and it's not done yet. A new study of Bennu tracking data gives us fresh clues on a ...

A new set of computer simulations suggests that there was once a fifth giant planet in addition to Jupiter, Saturn, Uranus, and Neptune.

Statistically, some of the most successful dynamical evolution simulations have initially included a hypothetical fifth giant planet, of ice giant mass, which gets ejected by a gas giant during ...

About 500 light years away, the fifth planet orbiting a small dim star called Kepler-186 has caught scientists' eyes as being not only roughly Earth-sized, but also within what's called the ...

Hypothetical Planet 9 accounts for the movement of several trans-Neptunian comets, asteroids, and dwarf planets, but scientists can't find it.

We haven't observed Planet 9 of our solar system directly, but the mathematical models predicting its existence are being taken seriously by the astronomer community.

A team of American astronomers announced the discovery of a fifth planet around a star called 55 Cancri.