When did Pluto stop being a planet, and why? Pluto was always in a tough spot when it came to being a planet. Just 1,477 miles across, it's only one-fifth the diameter of Earth.

The astronomers at Lowell Observatory in Arizona are showing Pluto some love on the 95th anniversary of its discovery, regardless of whether we call it a planet or not.

Pluto was discovered in 1930 in Arizona, but in 2006 scientists decided to cut Pluto from the planetary line up. Here is why Pluto isn't a planet.

The post Scientists Might Just Have Discovered Another Dwarf Planet Sibling For Pluto first on TwistedSifter. In 2006, Ceres – located in our solar system’s main asteroid belt – was officially ...

The New Horizons spacecraft left Earth in 2006 and began a 9-year journey that would result in it flying over Pluto on July 14, 2015, at a height of 7,800 miles (12,550km) above the planet's surface.

Pluto was the little planet that could — until it couldn’t. Discovered in 1930 at Lowell Observatory in Flagstaff, Arizona , Pluto was hailed as the ninth planet in our solar system.

Pluto's demotion was partially caused by us getting better at spotting planets (or "dwarf planets," if you prefer). In the early 2000s, astronomers identified Haumea, Eris, Makemake, and other ...

Lowell's sixth annual "I Heart Pluto Festival" will honor the remote icy world that was reclassified as a dwarf planet in 2006 and originally found at that location on Feb. 18, 1930.

Pluto's reign. For decades, students learned the phrase "My Very Educated Mother Just Served Us Nine Pizzas" to remember the order of the planets in the solar system: Mercury, Venus, Earth, Mars ...

Pluto was discovered 95 years ago on Feb. 18, and even though it was demoted nearly two decades ago, it remains a fascinating part of our solar system. "Pluto is a complex and mysterious world ...