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 ...

The relative quantities of volatile gases like methane and ethane can reveal key details about distant Kuiper Belt objects.

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 ...

People's profound connection with the Solar System led them to feel a remarkable sense of sympathy for Pluto when it was ...

Although Seeing in the Dark doesn't directly discuss Pluto, it does celebrate the joy of observing planets. Viewers who watch the show may wonder what happened to Pluto in 2006 and whether any of ...

“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.

A stronomer Percival Lowell founded his Arizona stargazing lab in 1894 to aid in his search for life on Mars. While that quest is still ongoing, the observatory made history as the place where ...

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.

A surprising chemical difference between Pluto and Sedna, another dwarf planet in the distant Kuiper Belt, is helping scientists nail down their respective masses, a new study reports.