Just the third-ever confirmed interstellar object has been detected in our solar system. Here's what we know. (Spoiler: It's ...

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 ...

When I was a kid, there were nine planets. Now we know of thousands! But that includes exoplanets, alien worlds that orbit alien suns. Only eight planets call our solar system home. Or there might ...

Our solar system right now looks nothing like what it originally looked like," Pitts said. "Look at a solar system like this one, where the planets are in this nice synchronicity and look at a ...

Our solar system may have a ninth planet after all, following the declassification of Pluto nearly two decades ago, researchers say. ABC News. Video. Live. Shows. Shop. Log In. Stream on.

The age of the solar system is precisely determined as 4.54 billion years old, with a 1% uncertainty, using radiometric dating of terrestrial rocks, lunar samples, and meteorites.

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 ...

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 ...