Our solar system’s origin story spans billions of years and involves clouds of gas, cosmic collisions, and planetary ...

Today, it’s believed that Jupiter and Saturn, the largest planets, were the first to fully form, both within a few million ...

The solar system is our cosmic neighborhood, made up of the sun and everything that orbits it — planets, moons, asteroids, comets, and even dust and gas. The order of the planets in the solar ...

Astronomers find evidence of a possible ninth planet beyond Neptune, reigniting the debate about the formation of the Solar ...

For decades, our solar system was thought to have nine planets, with Pluto considered the smallest and farthest. But in 2006, ...

Q: Why do the planets all orbit the Sun in the same plane? —Randi Eldevik | Stillwater, Oklahoma Because of the way the Sun formed, explains David DeVorkin, a senior curator in the space history ...

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 ...