An unidentified flying object or UFO refers to an unusual anomaly in the sky that cannot be readily identified as a known object. The first widely reported UFO sighting in the United States was in 1947 by pilot Kenneth Arnold, from whose report the term "flying saucer" originated. UFO sightings remain unexplained anomalies in the sky.

1. ALIENS
An unidentified flying object, often abbreviated UFO, is an unusual
apparent anomaly in the sky that is not readily identifiable to the
observer as any known object.

2. •The first widely reported UFO sighting in the United States came from
pilot Kenneth Arnold in 1947, it was from his report that we get the
term, ‘flying saucer’