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

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 form in ...

Ever since the first explorers charted the outer reaches of our Solar System, its true boundaries have remained hazy. While the Voyager probes have gone far into interstellar space, our Sun’s ...

"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 ...

This article was originally featured on The Conversation. 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 ...

CAPE CANAVERAL, Fla. (AP) — Astronomers have discovered the earliest seeds of rocky planets forming in the gas around a baby sun-like star, providing a precious peek into the dawn of our own solar ...

There’s a bit of a paradox about our galaxy: it’s both jam-packed with stars and cavernously empty. The Milky Way is crowded in the sense that it holds hundreds of billions of stars, as well as ...