For the better part of a century, we believed there were nine planets in our solar system, with Pluto being the farthest from the sun. Since the discovery of more Pluto-sized dwarf planets, that ...

Clyde Tombaugh discovered Pluto in 1930 at Lowell Observatory in Flagstaff. Here's how Pluto won - and lost - its planetary ...

Why was Pluto reclassified as a dwarf planet? One might think that it’s purely a matter of size. Mercury, the smallest of the ...

A new model that incorporates data gathered by the JWST could help scientists understand the composition and mass of objects ...

“New Horizons shattered a major paradigm of planetary science,” says Alan Stern, the mission’s principal investigator. “Pluto turns out to have as much complexity as Mars or Earth, so much so that I ...

Forbes contributors publish independent expert analyses and insights. Jamie Carter is an award-winning reporter who covers the night sky.

Gonggong is a dwarf planet and a member of the scattered disc beyond Neptune. As of 2019, its distance from the Sun is 88 AU, and it is the sixth-farthest known Solar System object.

The ringed gas giant Saturn has officially replaced Jupiter as the planet in our solar system with the most moons. The ...

Today NASA said that the Dawn spacecraft has fallen out of contact with Earth, presumably because it’s run out of the thruster… Read More The once-mysterious bright spots shining on the surface of the ...

The dwarf planet was there all along, waiting to be discovered, but it wasn’t what astronomers thought they would find. Pluto is just 1,400 miles wide, about half the width of the U.S. "It ...

Arizona in 1930 and was considered our ninth planet until 2006. The International Astronomical Union reclassified Pluto as a dwarf planet because it does not clear its orbit of other debris.