On July 14, 2015, NASA's New Horizons spacecraft arrived at Pluto for the first time. The craft flew within 7,700 miles of the planet and is sending back reams of data and the highest resolution ...

January 5, 2005, is an astronomical anniversary that is not really marked but should be. It saw the discovery of dwarf planet Eris and how those very observations led to a new way to describe the ...

Pluto, our power planet of seismic change, is stationing direct in the sign of the sea goat for the final time in our lifetimes. On Friday, Oct. 11, Pluto will go direct at a fateful 29 degrees of ...

Neptune’s largest moon, Triton, and the dwarf planet Pluto may have shared a common origin before being separated in the early solar system, an analysis of their composition suggests. Triton and Pluto ...

The planet Neptune wobbled in its orbit around the Sun. That could only mean one thing, astronomers said: There was a ninth planet out there, somewhere, lurking in the fringes of the solar system.

"This mission should be able to image the whole of Pluto. It should be phenomenal." When NASA's New Horizons spacecraft sped by Pluto in 2015, it revealed an incredible world of ice and haze carved by ...

Astronomers using the James Webb Space Telescope have peered into a mysterious blue haze cloaking the surface of Pluto — and discovered that it’s controlling the dwarf planet’s climate and atmosphere.

When the International Astronomical Union (IAU) demoted Pluto from a planet to a dwarf planet in 2006, it surprised a lot of people, including some scientists. Even many years later, some astronomers ...