1897 April 17 — 1:30 a.m. R. E. Draughon, a night watchman at a lumber plant in Beaumont, Texas, sees a “globular” object with a bright light the size of a star in one end. It is moving to the northwest at a high altitude. 

1897 April 17 — 6:00 a.m. An airship is said to collide with the tower of Judge James Spencer Proctor’s windmill in Aurora, Texas, causing it to explode and strew debris over several acres. The pilot (reportedly “not of this world,” or a “Martian” according to an alleged Army Signal Service officer named Thomas Jefferson Weems from nearby Fort Worth), does not survive the crash and is buried “with Christian rites” at the Aurora Cemetery. Wreckage from the crash site is either dumped into a nearby well located under the damaged windmill or ends up with the alien in the grave. Adding to the mystery is the story of Brawley Oates, who purchases Judge Proctor’s property around 1935. Oates cleans out the debris from the well in order to use it as a water source, but later develops an extremely severe case of rheumatoid arthritis, which he claims is the result of contaminated water from the wreckage dumped into the well. As a result, Oates seals up the well with a concrete slab and places an outbuilding on the spot in 1945. The entire yarn is widely regarded as a hoax, although Proctor’s windmill apparently did exist. https://en.wikipedia.org/wiki/Aurora,_Texas,_UFO_incident

1897 April 17 — 8:30 p.m. A large white light attached to a cigar-shaped object passes over Trenton, Tennessee, at an altitude of about 1,500 feet. It has a red light on the left side and a green light on the right. The object remains in sight for 5 minutes then disappears to the east. 

1897 April 17 — 9:00 p.m. George Alverson, Alex Oxford, and Charley Hunter are walking on Manchester Street near the Cincinnati Southern Railway trestle bridge in Lexington, Kentucky. An airship lands and settles in a vacant lot about 600 feet away. They hurry forward but are stopped by a man who has just emerged from the machine. He is carrying a bucket, which he fills with water from a nearby spring. He declines to answer any of their questions, reenters the airship, and flies away to the southeast.

1945 April 17 — Maj. Gen. James P. Hodges writes a memorandum to Gen. Henry H. “Hap” Arnold, saying that infrared devices are now available to take photographs of “balls of fire” in the Pacific. http://www.project1947.com/fig/1945a.htm

April 17 — 11:00 p.m. Mr. and Mrs. James L. Hendry see a “beautiful light” in the eastern sky from their house in Fisherville, Kentucky. It glows and recedes in brilliance as it approaches, casting a light downward. After 10 minutes, it goes out like a snuffed candle.

1950 April 17 — Newsweek publishes an article, “Flying Saucers Again,” on crashed saucers.

1950 April 17 — More than 15 people report seeing a UFO for 20 minutes at 2,000 feet on the eastern horizon at Los Alamos, New Mexico. One scientist watches the object through a telescope and says it looks flat, circular, metallic, and roughly 9 feet in diameter. It moves faster than any conventional aircraft. http://sohp.us/collections/ufos-a-history/pdf/GROSS-1950-Apr-July.pdf 

1952 April 17 — 12:58 a.m. Four high-altitude contrails heading east-southeast toward Alaska are seen by NORAD defense observers at Nunivak Island, Alaska. 

1952 April 17 — 5:10 a.m. Radar at Caswell Air Force Station [now closed] in Limestone, Maine, tracks five unknown targets headed southwest into the US. Three are later identified as off-course civilian airliners, while two remain unidentified. A nationwide Air Defense Readiness Alert is declared at 5:11 a.m. SAC is notified to prepare launch of nuclear missiles. The alert is canceled at 7:40 a.m. 

1952 April 17 — 12:05 p.m. Air Force T/S Orville Lawson, Rudy Toncer (sheet metal shop foreman), and sheet metal shop workers R. K. Van Houtin, Edward Gregory, and Charles Ruliffson at Nellis Air Force Base, near Las Vegas, see 18 circular objects flying an easterly course that carry them over or very close to the Nevada Test Site. They watch the objects for about 30 seconds. 

1952 April 17 — Dewey Fournet Jr. responds to a reporter from the Baltimore Sun who has asked about details of the Blue Book investigation with a two-and-a-half-page memo, vagued up a bit, but essentially saying that “nothing detrimental to our national security has materialized from these incidents.”

1959 April 17 — George Adamski meets with Sisir Kumar Maitra, head of the Department of Philosophy and dean of the Faculty of Arts of Banaras Hindu University in Varanasi during a stopover in Kolkata, India. https://www.the-adamski-case.nl/his-mission/global-reach/world-tour/

1966 April 17 — 5:00 a.m. Portage County (Ohio) Deputy Sheriff Dale F. Spaur and Deputy Wilbur Neff are 4 miles east of Randolph, Ohio, when they see a moving light through some trees at the top of a small hill along the road. The light is headed in their direction. They have heard of a UFO reported over police radio that night and figure this must be what was seen. The object hovers 50–100 feet in the air, bathing the two officers in a bright light. Spaur’s eyes water up. They rush to the cruiser and radio the station; the dispatcher says to wait there until a car with a camera arrives. The object makes some sharp maneuvers, and Spaur drives toward it cautiously. The UFO is 18–24 feet thick and about 35–45 feet in diameter. The object is so bright he hardly needs his headlights to drive. It speeds up whenever Spaur accelerates, and soon he is driving at 80 mph. As the UFO reaches Mahoning County, the pursuit is being broadcast over police radios in three counties. As they reach East Palestine, Ohio, Patrolman H. Wayne Huston sees the UFO and follows Spaur and Neff, at times reaching 100 mph. Just before 5:30 a.m., two police officers in Salem, Ohio, see the UFO as a “bright ball” much larger than a jet. They also see three jets following it, apparently Air Force Reserve planes from Youngstown, Ohio. Police officer Frank Panzarella in Conway, Pennsylvania, sees the UFO, very bright and in the “shape of a half of a football.” He hears on his radio that a jet interception is in progress. Now in Pennsylvania, Spaur and Neff are given orders to abandon the chase. For most of the event, the object has remained at 1,000 feet, but now it rises to 3,500 feet and hovers. Then it shoots even higher and disappears. In 30 minutes, many police and civilians have seen the UFO. Panzarella alerts the Rochester, Pennsylvania, police operator, John Beighey, and asks him to contact the Greater Pittsburgh International Airport. Beighey calls Panzarella and says the Air Force wants to talk to the police witnesses. Spaur, Neff, and Huston go to the Rochester, Pennsylvania, police station and Spaur phones the USAF station at Pittsburgh. Spaur speaks to some colonel who tries to convince him he has seen something conventional. NICAP’s William B. Weitzel, a philosophy professor, begins his own investigation, tracking down witnesses. Within a few weeks, he or his NICAP associates have interviewed all the police officers, as well as several others who have figured in the UFO chase, either as dispatchers or as those who overheard the radio communications. NICAP members also interview some civilians who claim to have seen a UFO at the same time of the chase and/or had monitored police scanners. 

1977 April 17–23 — An International Congress on the UFO Phenomenon is held in Acapulco, Mexico, organized by Mexico City businessman Guillermo Bravo. Speakers include J. Allen Hynek, Jacques Vallée, John A. Keel, William Spaulding, Walt Andrus, and Dennis Hauck. Prime Minister Eric Gairy makes a strong plea for a United Nations program to investigate UFOs.