Once the quirky underdog of our solar system, Pluto held planetary status until 2006, when it got a cosmic demotion that still stings space fans. Discovered in 1930, Pluto was the ninth planet for ...

In 1930, scientists discovered a small celestial body on the outer edge of our solar system. They called it Pluto and classified it as a planet. However, the International Astronomical Union (IAU) — ...

The science community may be ecstatic over the discovery of a ninth planet, but the former planet "Pluto" had a totally different reaction. Hours after scientists announced there's solid evidence of ...

The heart's brightness arises from sunlight reflection, while red patches, formed by tholins, showcase Pluto's atmospheric intricacies and ongoing discoveries in the Kuiper Belt.

It's going on two years since the International Astronomical Union rewrote its definition of a planet and busted Pluto down to something it called a "dwarf planet." But it's not a done deal, says Mark ...

In a span of 30 years — from the first moon rockets in 1959 to the Voyager 2 flyby of Neptune in 1989 — NASA spacecraft introduced the world to close-up views of the bodies in our solar system.

1. What is a planet? -- 2. Seven perfect planets made of aether -- 3. The Earth becomes a planet -- 4. Sixteen planets -- 5. Not everything that orbits the Sun is a planet -- 6. Uranus! -- 7. The ...