Using Pluto as an example, this celestial body, once considered the ninth planet, was redefined as a dwarf planet in 2006.

Pluto's unusual eccentricity and tilt is likely due to its interactions with neighboring Neptune and other giant planets, ...

By Will Dunham WASHINGTON (Reuters) -Astronomers using the Hubble Space Telescope have observed a white dwarf - a highly ...

Earth is the only planet in our solar system with a single moon, making it a rare phenomenon for a planet of its kind.

It has taken nearly a decade and 3 billion miles to get there, but scientists are about to get their first look at Pluto. The New Horizons spacecraft is closing fast on the tiny world once thought to ...

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 ...

The methane gas may constitute a rarefied atmosphere, or it may come from erupting plumes on Makemake’s surface.

Normally when a medium-size star dies, it blasts away the bulk of material in its system. The Hubble discovery was surprising ...

Using advanced models, SwRI led new research that indicates that the formation of Pluto and Charon may parallel that of the Earth-Moon system. In the resulting “kiss-and-capture” regime, Pluto and ...

Think you can spot Pluto? On July 25, the famously elusive dwarf planet reaches opposition—its best and brightest moment of the year. That makes now the ideal time to try to catch a glimpse of it from ...