Only eight planets call our solar system home. Or there might still be nine if some astronomers are correct about an as-yet undiscovered large body out past Neptune.

The planets in order from the Sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. If you include the ...

I/ATLAS, earlier known as A11pI3Z, is only the third interstellar visitor to be discovered passing through our corner of the ...

Rocky bodies called protoplanets were thought to have formed slightly earlier in the inner solar system than those beyond the ...

Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of collapsing gas created our Sun, the first thing to ...

A 9th planet in our solar system might be found — and no, it’s not Pluto. Is there another planet out there? Researchers say they have hints of a new candidate. Julia Musto. in New York.

Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of collapsing gas created our Sun, the first thing to ...

Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky A cloud of collapsing gas created our Sun, the first thing to ...