What Does UFO Stand For?

What does UFO stand for? Breaking down U, F and O

The three letters hold three words, and each one narrows the meaning:

Put together, the phrase is careful and neutral. It describes what a witness saw, not where it came from. An airline pilot who spots an odd light and cannot name it has seen a UFO in the strict sense, even if it later turns out to be a balloon.

Where the term UFO came from

Before the 1950s, newspapers usually wrote "flying saucer" or "flying disc" after a wave of sightings in the late 1940s. The US Air Force, which was collecting and studying reports, wanted a plainer term that did not suggest a shape or a source. "Unidentified flying object" is widely credited to Air Force investigators of the early 1950s, and the short form spread from their reports into the press.

The word "ufology," for the study of UFO reports, came later and is used mostly by hobbyists and writers rather than scientists. Both terms are now part of everyday English.

UFO vs UAP: why officials changed the name

Recent US government and military reports use UAP instead. It first stood for unidentified aerial phenomena and was later broadened to unidentified anomalous phenomena, so it can cover things seen underwater or in space, not only in the air.

• UFO suggests a solid object that flies.
• UAP covers any unexplained reading, sighting or sensor track, solid or not.

Officials say the newer term is meant to lower the stigma around reporting and to focus on data. In practice, news stories often use both, and most readers treat them as near synonyms. For other agency and defense letters, see the government acronyms section, which also covers NASA.

How to say and write UFO

You will hear two pronunciations. Many people say the letters, "U F O," which makes it an initialism. Others say "YOO-foh" as one word, which makes it an acronym. Both are standard.

• Write it in capitals without periods: UFO.
• For more than one, write UFOs; skip the apostrophe.
• Use "a UFO" in writing, since the letter U begins with a "you" sound.

The acronym vs abbreviation page goes deeper into how initialisms and acronyms differ.

UFO in real sentences

• "The bright dot everyone called a UFO was the planet Venus low in the west."
• "Two pilots filed a UFO report after the flight."
• "Our town has an annual UFO festival with costumes and a parade."
• "The documentary looks at UFO sightings near military bases."
• "He has been a UFO buff since he was a kid."

Common explanations for UFO sightings

Investigators find that most reports fit into a short list of known causes:

1. Planes and helicopters seen at odd angles or at night.
2. Weather and research balloons, which can drift high and catch sunlight.
3. Satellites, including long strings of small satellites passing in a line.
4. Bright planets such as Venus and Jupiter near the horizon.
5. Drones, kites, sky lanterns and birds reflecting light.
6. Camera effects such as lens flare and reflections on a window.

A sighting that stays unidentified after this kind of check is still not proof of anything beyond the fact that no one could pin it down. Keeping that distinction clear is what the word unidentified is for.