Pluto was reclassified as a dwarf planet in 2006. 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 ...

With sapphire waterfalls, lava rain and orbits around dead stars, these distant worlds push the limits of what’s possible.

The famous 87-year-old telescope at Lowell Observatory that was used to discover Pluto needs to be renovated so it can seek out the dwarf planet once more.

A pair of dwarf planets lurking in the outer reaches of the solar system could still be geologically active, increasing the chances that they could support alien life, a new study suggests. The ...

NASA/JPL-Caltech Sky gazers across the U.S. will have a chance to see an extraordinary celestial event on Friday as all of the planets in our solar system will appear in the evening sky. This ...

Within the first 72 hours of June, it won’t be a starman waiting in the sky, but what you’ll see could still blow your mind. At dawn on June 3, Mercury, Mars, Jupiter, Saturn, Uranus and Neptune will ...

If you've got any interest in skygazing, this is your week. A stunning planet parade is now visible in the night sky. A planet parade is when several of our solar system's planets are visible in the ...

Things have been a mess since Pluto's demotion. When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. In 2006, the International Astronomical Union ...