for how long people know the existence of UFOs???

Answer 1

Egyptians had hyroglyphics that looked like UFOs. Unusual aerial phenomena have been reported throughout history:

During the reign of the Pharaoh Thutmose III around 1450 BC

The army of Alexander the Great in 329 BC

In 1235 the army of Oritsume in Japan saw mysterious lights in the sky

Circa 1491-1492, famous explorer Christopher Columbus had an account, in his journal, of lights that had seemed to come out of the sea, and vanished into the air.

and many others...

Answer 2

people know the existence of UFOs since ancient times in many ancient temples archaeologist have found strange figures which they believe are images of UFOs

Answer 3

as far as modern human being's empirical knowledge can accept; over 15,000 years. Dogon people in Mali West Africa knew already what modern astronomy discovered in 1990's. Sirius has a companion star/planet SIrius C. Who told them so? I would only conclude somebody from there of course.
"The Dogons calendar is quite non-traditional in that its fifty year cycle is based neither on the Earth's rotation around the Sun (as is our Julian calendar) nor the cycles of the Moon (a lunar calendar). Instead, the Dogon culture centers around the rotation cycle Sirius B which encircles the primary star Sirius A every 49.9 - or 50 years"

Answer 4

Nobody has substantiated the claim yet that there are UFO's. People have suspected and talked about it for years, but there is no proof.

Answer 5

There r no UFOs, it's just an imagination

Answer 6

Roswell 1947. Of course, aliens also built the pyramids, so I guess sometime around 3000 BC.

Answer 7

I M Damn Sure exactly 3.98725 Trillions years before...

Answer 8

There are no UFOs. Welcome to the real world.

Answer 9

Decades...i guess......and of course with it, there are hoax too.