Friday, August 17, 2012

Discovering Pluto

In the old days astronomers would often take pictures of the same area of the sky several nights apart. They could then study the images in a binocular viewer that combined the images. By closing one eye or the other the astronomer could spot planets, comets, or dwarf planets, all of which moved across the stars, which don't move.

I took these two images four nights apart using the 16" Slooh robotic telescope at Mount Teide observatory in the Canary Islands. Can you spot the object which moves between the two 5-minute exposures? If you can, just think: If you had noticed it 83 years ago, YOU would have been listed as the discoverer of Pluto. -- D.H.