Our Solar System has eight planets, a few dwarf planets and more than 200 moons. But wait. Are you seeing double? Or did ...

As far-fetched as it may seem, quirks of orbital mechanics could allow hundreds of planets to be packed around a star ...

Learn how Pluto nearly kept its planet status in a proposed 12-planet Solar System as its demotion marks its 20th anniversary. Eight days before Pluto lost its planetary status, it appeared ready to ...

Add Yahoo as a preferred source to see more of our stories on Google. About 4.6 billion years ago, a celestial cloud collapsed, paving the way for our solar system to form. Then, a nebula with strong ...

A powerful new tool comes online this year that could help astronomers locate the mysterious planet hiding somewhere beyond Neptune altering object orbits. If you get the question in Trivial Pursuit ...

Add Yahoo as a preferred source to see more of our stories on Google. Are planets in the solar system that are closer to the Sun older than the ones further away? – Gavriel, age 10, Paducah, Kentucky ...

You can be moving at extraordinary speed and still feel completely stationary. The reason comes down to the difference between velocity and the changes in motion your body can actually detect.

The Sun’s death is not an event the planets will quietly survive—it is the trigger for their orbital undoing.” ...

The fate of our solar system is written in the stars—well, one star to be precise: the sun. Estimates of what the end will ...