February 18 marks the discovery of Pluto by astronomer Clyde W. Tombaugh. The discovery reshaped the understanding of the solar system, as Pluto was long considered ...

On February 18, 1930, the American astronomer Clyde Tombaugh discovered Pluto! Before he discovered Pluto, another astronomer ...

From 1905 until his death in 1916, Percival Lowell searched for a ninth planet, which he called Planet X. Lowell had predicted the planet based on irregularities in the orbit of Uranus. In 1929, ...

February 18 holds a special place in history. Martin Luther's death in 1546 sparked the Protestant Reformation. Mark Twain's ...

Clyde Tombaugh, who was born on this day in 1906, grew up on a farm in Kansas and was captivated by sights of the moon and ...

On 2/18/1930, American astronomer Clyde Tombaugh discovered Pluto. We celebrate the plucky dwarf planet with a scale model replica of the solar system in Maine.

CAPE CANAVERAL, FL -- Come Tuesday, Clyde Tombaugh will pass within 7,800 miles of the icy world he discovered 85 years ago. His ashes are flying on NASA's New Horizons spacecraft on humanity's first ...

We classified Pluto before really understanding it—just like we reduce people to job titles or put names on relationships ...

For decades, scientists have theorized that Pluto's unusually large moon Charon formed through a process similar to Earth's moon—a massive collision followed by the stretching and deformation of fluid ...

We now know that Pluto, the dwarf planet formerly known as a planet, has one more moon orbiting it. Using the Hubble Space telescope, astronomers have discovered Pluto's fifth moon. NPR's Joe Palca ...

Pluto's discovery by Clyde Tombaugh, key political changes in Scandinavia and America, plus cultural and scientific milestones.