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 ...

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 ...

If you're an early riser, you're in for a treat. On Sunday, Aug. 10, six planets — Mercury, Venus, Jupiter, Saturn, Uranus and Neptune — will line up in what is called a "planetary alignment." This ...

This article first appeared on Wired.com. On August 10, six planets — Mercury, Venus, Jupiter, Saturn, Uranus, and Neptune — will line up in an arc in the night sky. Four of these planets — Mercury, ...

Astronomers are closing in on one of the most tantalizing possibilities in planetary science, evidence that a previously unknown world may be lurking in the outer reaches of the solar system. The ...

(CNN) — The search for an unknown planet in our solar system has inspired astronomers for more than a century. Now, a recent study suggests a potential new candidate, which the paper’s authors have ...