The discovery of the Kuiper Belt revealed thousands of icy objects near Pluto, challenging its status as a planet. After the ...

Twenty years after Pluto lost its planetary status, the debate continues as scientists still disagree over what defines a ...

Pluto lost its planethood for a very specific reason. Whether or not that’s a good reason depends on who you ask.

Twenty years after Pluto became a dwarf planet, people are still fighting over its status. Experts explain why the debate ...

Picture a star, about half the sun’s mass shining with a dim red light. Lumbering around it on a 5,000-year orbit is a huge ...

On the 20th anniversary of Pluto’s infamous demotion, Mike “Pluto Killer” Brown explains why any reversal of that decision ...

A 24-year-old observatory assistant from the Midwest discovered Pluto. Clyde Tombaugh, born in 1906 in Streator, Illinois, ...

M onday, August 24 marks the 20th anniversary of the International Astronomical Union (IAU) vote to adopt a formal definition ...

August marks 20 years since astronomers made one of the most controversial decisions in modern astronomy: Pluto was no longer ...

Those who supported Pluto’s demotion included Neil DeGrasse Tyson ...

The first observed interstellar object zipped through our solar system in October 2017 -- and astronomers have been trying to understand it ever since. Scientists scrambled to observe the object ...