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 ...

Scientists may have discovered a dwarf planet far beyond Neptune — an unearthing that may disprove a longstanding theory about the possibility of a giant ninth planet. The dwarf planet's existence ...

When you gaze up at the constellation Hercules, you are looking out the front window of the spacecraft called Earth. Our planet is hurtling at some 45,000 mph (72,000 km/h) toward the star Lambda (λ) ...

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 ...

A new Tatooine-like planet outside the solar system may orbit two failed stars, scientists reported Wednesday. Subscribe to read this story ad-free Get unlimited access to ad-free articles and ...

Add Yahoo as a preferred source to see more of our stories on Google. Our solar system may have a ninth planet after all, researchers say. The possibility that an additional planet may be hidden far ...