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 ...

Curious Kids is a series for children of all ages. If you have a question you’d like an expert to answer, send it to [email protected]. Are planets in the solar system that are closer ...

The formation of our solar system from a singular nebula raises an intriguing question: why did each planet develop with a ...

When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. Beyond the familiar planets lies a fascinating frontier filled with icy worlds, mysterious orbits ...

Add Yahoo as a preferred source to see more of our stories on Google. An illustration showing Planet Nine, a hypothetical, undiscovered planet in our solar system. New research now suggests the ...

Our solar system is made up of the sun, the eight known planets and the dozens of moons that circle those planets. But then there are innumerable asteroids, comets and dwarf planets wandering around.