Dozens of NASA's spaceflight missions that launched from Florida could be in jeopardy under a budget proposal from the Trump ...

Scientists say a new planetarium show about the Milky Way has helped them unlock one of the solar system’s many secrets.

A recently discovered celestial body is rewriting our knowledge of the Kuiper Belt and maybe challenging the existence of the ...

Almost 20 years after Pluto was infamously downgraded from its status as a planet, scientists now believe they have ...

In a distant region of space thought to be empty, a newly discovered dwarf planet inspires a debate about the existence of a giant planet hiding out there.

Discovery of 2017OF201, a large trans-Neptune Object, challenges previous beliefs about the Kuiper Belt and hints at the existence of a theoretical Planet Nine.

Scientists have identified an object about 435 miles (700 km) wide inhabiting the frigid outer reaches of our solar system that might qualify as a dwarf planet, spotting it as it travels on a highly ...

A potential new dwarf planet has been discovered in the outer reaches of the solar system, and its existence poses the ...

Other dwarf planets in the region have been discovered in the years ... On July 14, 2015, New Horizons conducted a flyby past Pluto and its moons, giving scientists back on Earth their first ...

Pluto was discovered ... for Planet Definition 24 August 2006 in Prague. The resolution demoted Pluto from its status as the ninth and outermost planet of the solar system to that of a dwarf ...

New Horizons discovered that Pluto is home to the largest glacier ... Pluto struggles for respect, with the “dwarf planet” label continuing to rankle Pluto partisans. The IAU defends the ...

(Correction: An earlier version of this story misstated how far Pluto is from the sun. The correct number is 3.7 billion miles.) What was discovered ... Pluto as a dwarf planet.