I hadn’t heard of this until Kucinich mentioned it at the debate:
President Jimmy Carter’s widely-reported “UFO sighting,” which he made public while Governor of Georgia, was in fact a misidentification of the planet Venus. Several errors of identification within Mr. Carter’s report demonstrate that the eyewitness testimony of even a future president of the United States cannot be taken at face value when investigating UFO sightings.
The incident occurred in Leary, Georgia, about forty miles from Plains, on the evening of January 6, 1969. Mr. Carter was the local district governor of the Lion’s Club, and had come to Leary to boost the local chapter. While standing outdoors at approximately 7:15 pm, waiting for the Lion’s Club meeting to begin, Mr. Carter reported seeing a single “self-luminous” object, “as bright as the moon,” which reportedly approached and then receded several times. Mr. Carter reports that his “UFO” was in the western sky, at about 30 degrees elevation. This almost perfectly matches the known position of Venus, which was in the west-southwest at an altitude of 25 degrees. Weather records show that the sky was clear at the time of the sighting.
No other object generates as many UFO reports as the planet Venus. Venus is not as bright as the moon, nor does it actually approach the viewer, or change size and brightness, but descriptions like these are typical of misidentifications of a bright planet. Every time Venus reaches its maximum brilliance in the evening sky, hundreds of “UFO sightings” of this type are made. At the time of the Carter UFO sighting, Venus was a brilliant evening star, nearly one hundred times brighter than a first-magnitude star.
(via Bad Astronomy)