What are unidentified flying objects (UFOs)? UFOs are described as aerial airborne objects, or optical phenomena, that cannot be immediately explained or identified. UFOs first started becoming a topic of interest during World War 2, sparked by the development of rocket science. Later on, a conspiracy was formed that UFOs might be signs that extraterrestrial life exists and has visited Earth.

The first popular UFO sighting was in 1947 when a businessman named Kenneth Arnold claimed he saw a group of crescent-shaped objects flying in the sky while flying his plane in Washington. In 1948, the U.S. Air Force started Project Sign, an investigation focused on a large number of UFO sightings recently reported. This investigation soon gave way to Project Grudge, which then gave way to Project Blue Book. Project Blue Book lasted from 1952-1969, the most lasting of the U.S. government investigations into the UFO question. Over 12,000 sightings were recorded while Project Blue Book was in operation. In 1953, a group of scientists led by physicist H.P. Robertson was created by the CIA, with the purpose of reviewing the findings of Project Blue Book. They found that most of the UFO sightings could be explained by natural phenomena, so they weren’t a threat to the U.S., and they concluded that Project Blue Book’s records showed no evidence of extraterrestrial life.

Recently, there have been multiple unidentified objects flying over the U.S. Here is a quick timeline:

Feb 4- A Chinese spy balloon was shot down over the Atlantic Ocean.

The balloon was about the size of three buses and was flying at an altitude of 60,000 feet. China said that the device was a civilian aircraft that strayed into American airspace, but American officials believe it was meant to be used to spy on the military bases in Hawaii and Guam.

Feb 10– A U.F.O. was shot down over the waters of Alaska.

The unidentified object was most likely not a balloon and it was the size of a small car. The object was first detected on Feb 9 and was heading toward the North Pole.

Feb 11– A U.F.O. was shot down over Canada.

The object was taken down near the border of Alaska and described as a small, cylindrical object. It was unclear what the object was, but it was smaller than the spy balloon.

Feb 12– A U.F.O. was shot down over Lake Huron, just off Michigan.

The object had an octagonal structure with strings hanging off and was flying at about 20,000 feet. The object first appeared on Feb 11, flying over Montana.

Feb 7– The search for the objects’ remains was called off.

Because of difficulties posed by the weather conditions, the U.S. and Canada paused their searches for the unidentified objects’ remains.