Press "Enter" to skip to content

Discovering Pluto

The planet Pluto was discovered by astronomer Clyde Tombaugh on this date in 1930. He used a 13-inch astrograph to photograph and identify the planet. Tombaugh also believed in the possiblily of extraterrestrial activity and claimed to have seen UFOs

Johannes Hevelius, Machinae Coelestis Pars Prior [and Posterior]
[Celestial machines, or astronomical instruments]
, 1673-79.

In 2006 Pluto was designated a dwarf planet, minor planet 134340. Tombaugh may not have been too upset at this "downgrade", as Pluto was only one of many of his astronomical discoveries:

Tombaugh discovered nearly 800 asteroids during his search for Pluto and years of follow-up searches looking for another candidate for the postulated Planet X. Tombaugh is also credited with the discovery of comet C/1931 AN, though its orbit is currently unknown. He also discovered hundreds of variable stars, as well as star clusters, galaxy clusters, and a galaxy supercluster.—Wikipedia

Elizabeth Periale


Out of the darkness, the planet Pluto. Clyde W. Tombaugh, Patrick Moore.

The case for Pluto: how a little planet made a big difference. Alan Boyle.

Ninth planet news: information exchange for observers of Pluto-Charon mutual events.

Beyond Pluto: exploring the outer limits of the solar system. John Davies.

Clyde Tombaugh: discoverer of planet Pluto. David H. Levy.

One Comment

  1. Maureen Girard

    Just saw the Nova program about Pluto, and there was no mention of what will happen to Clyde Tombaugh’s homemade telescopes which were shown as still located in his garage.
    They should be in the Smithsonian!! Not only are they a part of the history of American astronomy, but more importantly, they demonstrate the ingenuity and creativity of scientists as they pursue knowledge.
    Those big tin cans fitted up with reflectors and fashioned out of old farm equipment tell more stories about science and the human quest for truth than a boatload of textbooks.

Leave a Reply

Your email address will not be published. Required fields are marked *