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

In 2006, the International Astronomical Union (IAU) decided that a large celestial object is a planet only if its gravitational orbit around the sun makes it round and if it’s big enough to ...

What do Uranus, Pluto, and an awe-inspiring celestial event have in common? They all converge on the iconic date of March 13.

Scientists at NASA for the first time have been able to observe the make up of Pluto and other small and icy celestial bodies in the outer solar system ... New data from the James Webb Space Telescope ...