United States.Dexter and Hillsdale: the 'swamp gas' sightings

In March 1966, southeastern Michigan was accumulating reports of lights at night, and two consecutive nights drew national attention. On Sunday, March 20, at about 8:35 p.m., the Washtenaw County sheriff's office received a call from a farm near Dexter, about 8 miles northwest of Ann Arbor: there was a strange object in the swamp, which had risen about 500 feet and returned to the ground. The main witness, farmer Frank Mannor, later told the Air Force's scientific consultant, the astronomer J. Allen Hynek, that he saw a light he took for a falling star that stopped over the swamp north of his barn, and that he and his son walked toward it. According to the sheriff's report, from about 500 yards they described a brown object with a quilted-looking surface, flat on the bottom and cone-shaped on top, with two lights at its ends that changed from blue-green to brilliant red and a yellowish light between them; when the deputies' flashlights appeared, the light intensified, went out, a whistle 'similar to the sound of a rifle bullet ricochet' was heard and the object passed over the Mannors.

Deputies Stanley McFadden and David Fitzpatrick searched the woods and the swamp without result. According to the Selfridge base telex of March 23, McFadden saw the lights and heard the sound, though not as close nor for as long as Mannor, and agreed with him; he later told the Blue Book team that he first took the light for a radio tower beacon and that it was about three quarters of a mile away. He told Hynek he had not seen the object, although he drew it. Fitzpatrick told Hynek he saw only a glow behind a rise, which brightened and dimmed slowly 'as though stage lights were being brightened and dimmed', and that it disappeared as he approached with his flashlight. Back at their car, onlookers told them one of the objects had hovered over their flashlights and departed west at high speed, and in the patrol cars waiting there they were told that four lights had hovered above them while they searched. Officer Hunnawill of Dexter and his wife said a ball of light passed very close to their car, and Hynek noted that, if the account was accurate, the light must have been very near. Sheriff's Patrol 19 saw bluish-green lights by another swamp, which disappeared when it tried to get closer, and the Chelsea police reported a similar object over the village. That telex, based on McFadden's report, describes the object as brown and 'like two soup bowls' placed one on top of the other, speaks of four objects and records that Mannor, who hunted the area often, stated 'positively' that the lights were not fires caused by natural gas in the swamp, and concludes that preliminary analysis gave no basis for disbelief in the sighting nor clue to its identity.

The next night, March 21, students in a Hillsdale College dormitory, about 45 miles to the southwest, saw from their darkened rooms red, yellow and white lights over a swampy hollow. They called the county Civil Defense director, William Van Horn, who saw nothing in that direction from his home; the state and city police came, searched the area and found nothing, but the students kept seeing lights, and Van Horn went to the dormitory and watched them. According to Hynek's report, his first impression was that they were marsh lights, until they grew brighter and appeared to rise; they rose and fell some four times between 11:30 p.m. and 1:45 a.m. on March 22. Van Horn said he saw between two lights a convex mass the students did not describe, and Hynek judged him a man who becomes enamored with an idea and loses objectivity. The press clippings in the file speak of 80 and of 87 students. Hynek spent three days in the area and talked with the deputies, with Van Horn, with two of the students and with eleven members of the University of Michigan astronomy department.

On March 25, at a press conference at the Detroit Press Club, Hynek proposed that the lights over the two swamps could be due to swamp gas, the will-o'-the-wisp, ignited by the phosphine produced by decaying vegetation, and warned that he could not prove it 'in a court of law'. The Air Force release added that at Hillsdale some young men had played pranks with flares and that the photograph circulated by the press, taken near Milan on March 17, showed the trails of the crescent Moon and Venus in a time exposure. The Blue Book record card closed the case as 'Other (MARSH GAS)'. The explanation was ridiculed nationwide; the House Republican leader, Gerald R. Ford, a Michigan congressman, called for a congressional hearing, and on April 5, 1966 the House Armed Services Committee heard Air Force Secretary Harold Brown and Hynek.

The case matters less for what was seen than for what it set off. At the April 5 hearing, Hynek said the Dexter and Hillsdale incidents were of little scientific significance and that he had left them out of his twenty unexplained cases because they were 'subject to simple, albeit somewhat unusual, explanation', but he used the occasion to ask that a civilian panel of scientists study the best cases. At the same session Brown presented the report of the Scientific Advisory Board's ad hoc committee, which had met on February 3 (the printed transcript says the 8th), before the Michigan events, and recommended contracting universities to investigate selected cases. The University of Colorado contract was announced on October 7, 1966, and the Condon Report cites the Michigan wave as probably the greatest furor of that year.

The explanation has layers, and they should be kept apart. For the Hillsdale lights, the Air Force documented pranks with flares, and the press in the file reports flare remains near the dormitories. For the glow over the swamps, the gas hypothesis is the one put forward by Hynek, the Blue Book card and the release, and in 1968 Condon considered it 'quite genuinely a possibility', though not established. Hynek set down the objections in his own report: it was not known whether swamp lights appear at near-freezing temperatures, one could ask why they had not been seen in those places before, and he had to set aside the testimony of those who believed they had seen an object. To that add the Selfridge telex, which took the report as factual with no clue to identity, Mannor's and Van Horn's flat rejection of the gas idea, and the accounts of moving lights over Chelsea and beside the cars. On the other side weigh the facts that, according to the Air Force release, the only two witnesses who described an object were never closer than about 500 yards, that the deputy who came closest saw only a glow, and that a wave of reports fed by the press included a photograph of the Moon and Venus and pranks with flares.