William K. Hartmann

Planetary science career

William Kenneth Hartmann (born 6 June 1939, New Kensington, Pennsylvania) is an American planetary scientist, space artist and writer. He earned a B.S. in physics at Pennsylvania State University and an M.S. in geology and a Ph.D. in astronomy at the University of Arizona. Early in his career he worked with Gerard Kuiper on lunar basin studies and on the Mariner 9 Mars mapping project, and later joined the Mars Global Surveyor imaging team. He is a senior scientist at the Planetary Science Institute in Tucson, which he helped found in 1972.

Hartmann is best known in planetary science for helping persuade the mainstream that a planet-sized body struck the early Earth and produced the Moon, the giant-impact hypothesis developed with Donald Davis. He was also a prolific popular communicator. With illustrator Ron Miller he produced The Grand Tour and The History of Earth, and he was the first recipient of the Carl Sagan Medal from the American Astronomical Society, awarded for public communication of planetary science.

The Condon Committee

In 1966 Hartmann joined the University of Colorado UFO Project, the Air Force-sponsored study directed by physicist Edward U. Condon, usually called the Condon Committee (see the Condon Committee article). His work centred mainly on photographic evidence, and he judged most of it unreliable or inconclusive. The study's final report, published in 1969 as Scientific Study of Unidentified Flying Objects, drew on his analysis, and he wrote the part that examined whether misinterpretation and misreporting could account for the phenomenon.

He singled out two cases as unexplained: the 1950 Great Falls, Montana, sighting and the 1950 McMinnville, Oregon, photographs.

McMinnville and the photograph question

The McMinnville case was the one that most engaged Hartmann. He obtained the original negatives from UPI and tested them. In his assessment he wrote that this was "one of the few UFO reports in which all factors investigated" pointed toward an unusual object, which he described as "an extraordinary flying object, silvery, metallic, disk-shaped, tens of meters in diameter, and evidently artificial." He did not claim certainty. He acknowledged that the tests did not rule out a small model hung from a nearby wire.

The assessment did not last. According to the McMinnville UFO photographs article, Hartmann later withdrew his positive view after the skeptic Robert Sheaffer sent him counter-research. The reversal shows that he treated the photographs as a physical problem to be tested, and that his judgement moved when the evidence did.

Assessment and legacy

Hartmann was not an advocate of extraterrestrial visitation, and his Condon-era work tended toward the view that most photographic evidence did not survive scrutiny. What set him apart from several colleagues was his willingness to say that a few cases resisted explanation. The report's overall summary, as quoted by J. Allen Hynek in his 1969 review, stated that the data were "compatible with but do not establish" the hypothesis that UFO reports are entirely misidentification, fabrication or poor reporting, and that "a very small part of the UFO phenomenon involves extraordinary events" (see the Hynek review of the Condon Report).

Critics on both sides have disputed the study's method and conclusions. Hartmann's own McMinnville reversal is one of the clearest illustrations of why the photographic record remains hard to settle. Hartmann's reputation rests mainly on planetary science, and his UFO role is a footnote to that career, but it is a documented one that has been argued over for more than half a century.