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 ...

A cloud of collapsing gas created our Sun, the first thing to form in our solar system. This happened about 4½ billion years ago.. Then the planets began to emerge, as the billions of particles ...

This process, called accretion, is how everything in the solar system – planets, moons, comets and asteroids – came into being. Telescopes can see young solar systems being born.

All of our solar system’s planets are lining up to parade through the night sky at once. This extraordinary celestial event will see the sky scattered with seven visible planets in what is known ...

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 ...

Astronomers now have a powerful new tool to uncover the faintest traces of exoplanets, galactic structures, variable stars, and fleeting cosmic events beyond our solar system. The Prime-focus ...

The solar system is primarily comprised of our sun — which makes up the vast majority of its mass — and the eight planets, which are split into three subcategories. First up are the rocky ...

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 ...

The conclusion of the current planetary alignment of the planets in our solar system is expected to occur on Friday night after dusk. The exact time varies based on a viewer's location.

This process, called accretion, is how everything in the solar system – planets, moons, comets and asteroids – came into being. Advertisement Article continues below this ad ...

Between February 25 and February 28, all seven planets in our solar system will be visible in the night sky. It's known as a planetary parade. You'll need a telescope for some of them, but you ...