50 Years of UFO SightingsUFO sightings counts, scaled at the left, are shown for every month, over 50 years.
Exceptional months are circled in green. July 1947 is right off the screen, October 1954 nearly so. The violet curve is a 6-month moving-average to show trends over the years.
Venus-Earth and Mars-Earth distances show as grey and red quasi-periodic curves, scaled at the right in Astronomical Units [AU]. One AU is the mean distance from Earth to the Sun. Planets are closest to Earth at the tops of each curve.
Note the slump of inactivity between 1958 and 1964, and also thru the 1980s. A much deeper and longer slump ( not shown ) occurred between the "great airship" sightings of 1885-1910 and the modern era displayed here.