Front-page story (see MISC-PBB2-1048) says that on April 18,1962, the Air Force Defense Command was puzzled by an aerial object that exploded and seemed to be a meteor, but had the unique distinction of being tracked by radar 70 miles northwest of Las ''Vegas, Nevada, as well as chased by jets, before it exploded in Nevada in a blinding flash. An Air Force Defense Command alert reported the object was tracked and traced over New York, Kansas, Utah, Idaho, Montana, New Mexico, Wyoming, Arizona and California, so that it's light covered almost as much area as that created by the big hydrogen space bomb test held later in the Pacific hundreds of miles high.
NORAD had tracked the object which had covered 10 states in 32 minutes but changed course over Utah. Now detected on GCA radar at Nellis the object is moving NE, but the Air Force explains this radar sighting as, a balloon!
Project 10073 Record Card and report of radar sighting. Blip. "Speed of object varied. Initial observation at 060 no elevation. Disappearance at 105 az 10,000' altitude. Heading tentively NE, however disappeared instantly to S."
Project Blue Book Documents in pdf or individual offsite form:
PROJECT 10073 RECORD CARD
Description of event and pr coverage, source unknown but in Bb files