¡SkyCaramba! Weekly astronomy blog for the week ending July 18, 2015
In astronomy, the credit for discovering something goes to the person who recognizes it for what it is. That’s not necessarily the person who saw it first. Some astronomical objects have been noted decades before they were discovered. The person who first saw Neptune died more than 200 years before someone discovered it.
Discovery photographs of Pluto in 1930
We may never really know how many planets, comets, asteroids, and other objects have been seen one or more times before someone drew or photographed it. Astronomers see so many things when observing, they can’t keep track of them all. Even after a drawing or photograph is made, it may take years before someone makes another observation that leads to a discovery.
We can illustrate the situation quite well with Pluto. Working at Lowell Observatory in Arizona in 1930, Clyde Tombaugh took pictures of the sky and compared them to look for moving objects. He noticed something different in two pictures taken on January 23 and January 29. To further prove something in the photographs had moved, the Lowell administrators pulled out a picture from the same patch of sky ...