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 may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far into the solar system was touted more than a century ago. But ...

Add Yahoo as a preferred source to see more of our stories on Google. Digital art of distant planet - Dottedhippo/Getty Images On August 24, 2006, our solar system lost a planet. It wasn't by ...

When you see art of our solar system as the planet orbit the sun, you may notice that Earth's orbit has a tilt. It is not a perfect circle. What's more, Earth is not the only planet that displays such ...

There have been questions about a mysterious ninth planet in our solar system for nearly a decade. Pluto was unseated as number nine in 2006. Now, a group of international researchers say they may ...

For decades, our solar system was thought to have nine planets, with Pluto considered the smallest and farthest. But in 2006, Pluto was officially reclassified as a dwarf planet by the International ...

The planets in solar do not have circular orbit around the Sun, including Earth which goes around in an elliptical orbit. A ...

An artist’s rendering of the theorized Planet Nine, back towards the sun. The planet is thought to be gaseous, similar to Uranus and Neptune. Hypothetical lightning lights up the night side. We get a ...

Estimating ages of specific events is one of the most difficult problems in astrophysics. While we have a precise (and probably accurate) age for the solar system, we do not have precise ages for each ...