The newcomer replacing Pluto presently goes by “Planet Nine.” If and when it finally shows up, it will get the honor of a ...

The potential discovery of a large planet beyond Neptune’s orbit could change everything we know about the Solar System.

There are eight official planets (sorry, Pluto) in our solar system: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and ...

In 2015, two astronomers from Caltech presented evidence that six objects past the orbit of Neptune were bunched ... better than in simulations where planet 9 was not included.

If Brown’s hidden world is real, Rubin will almost certainly find it or strong indirect evidence that it exists. “In the ...

The probe, equipped with Swiss instruments, has completed the last milestone before entering Mercury's orbit. This content ...

Astronomers are on the hunt for a mysterious ninth planet, known as Planet Nine, which could change our understanding of the solar system. Is this hidden world real, or just a myth?

Smaller gas giants are less likely to survive in such systems, surrounded by clashing planetary titans. With their lower ...

Billions of years ago, two icy worlds—Pluto and Chron—collided in the farthest reaches of our solar system. But rather than ...

Earth' 750 light-years away, with 8 Earth masses packed into 1.6x Earth’s size, orbiting its star in just 21 hours.