At just 23 years old, Tombaugh sent his drawings, unsolicited ... the discovery of a new planet. The search for Pluto did not begin with Clyde Tombaugh, to be fair. That distinction belongs ...

He then sent these drawings to Lowell Observatory ... the International Astronomical Union reclassified Pluto, separating it from the eight other "classical planets" and placing it with two ...

“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 ...

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

If you answered "Pluto's planethood," your grasp of the astronomical is excellent. Feb. 18 marks the 95th anniversary of the discovery of our outermost planet-not-planet. Here's what to know about ...

Pluto, discovered in 1930, was once considered the ninth planet in our solar system. In 2006, the International Astronomical Union reclassified Pluto as a dwarf planet because it doesn't meet all ...

A blue atmosphere, smooth areas, and youthful mountain ranges - this dwarf planet is full of surprises. When NASA's New Horizons probe flew past Pluto in July 2015, the images it returned astonished ...

"Tombaugh sent some of his drawings off to different places ... roughly where Lowell had predicted it would be. A ninth planet, Pluto, had been discovered. One of the most fascinating aspects ...