A molten planet is a planetary object; a surface or deep interior of which is mostly or wholly in a liquid-rock (magma) form ...

An exoplanet is what we call planets that exist outside of our own solar system. The first one was discovered in 1992, but as we get more powerful and precise telescopes and instruments, scientists ...

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. February will end the month not with an extra day but with an extra special celestial event. A planet parade will feature six ...

Is there a massive undiscovered planet on the outer reaches of the solar system? The idea has been around since before the discovery of Pluto in the 1930s. Labeled as planet X, prominent astronomers ...

Is there a massive undiscovered planet on the outer reaches of the Solar System? The idea has been around since before the discovery of Pluto in the 1930s. Labelled as planet X, prominent astronomers ...

A hazy, ultra-light “super-puff” planet, Kepler-51d, is hiding its secrets and challenging how scientists understand planet formation.

Did you miss the start of the planetary alignment last week? Well, don't worry, you'll still have a few more days to see it before the month is up. But this will be your last chance for the year.

On August 24, 2006, our solar system lost a planet. It wasn't by cataclysmic destruction, but rather by the vote of the International Astronomical Union, which declared that Pluto, considered the ...

A celestial event known as a planet parade will occur at the end of February. Six planets will appear in a diagonal line across the western sky an hour after sunset. Mercury, Venus, Jupiter, and ...