Monday, February 18, 2008

Discovered This Day: The Former Planet Pluto

In 1930, the planet Pluto was discovered by Clyde Tombaugh, the only planet to be found by an American astronomer, after three decades of work at Lowell Observatory in Flagstaff, Arizona. Before Tombaugh was born, Percival Lowell had searched unsuccessfully for Pluto, a ninth planet whose gravity would explain deviations in the positions of Uranus and Neptune. In his will he decreed that the hunt should continue. That meant using a telescope to photograph tiny pieces of the sky by night, then and sifting through the millions of star images by day for one dim dot that moved. When Lowell Observatory director Vesto Slipher hired him, a Kansas farmboy, Clyde Tombaugh threw himself into the search in Apr 1929. From Today In Science History.

The above picture captures the true colors of Pluto as well as the highest surface resolution so far recovered. Although no spacecraft has yet visited this distant world, the New Horizons spacecraft launched early this year is expected to reach Pluto in 2015. The above map was created by tracking brightness changes from Earth of Pluto during times when it was being partially eclipsed by its moon Charon. Pluto's brown color is thought dominated by frozen methane deposits metamorphosed by faint but energetic sunlight. The dark band below Pluto's equator is seen to have rather complex coloring, however, indicating that some unknown mechanisms may have affected Pluto's surface. Info from HERE

More info HERE.