That event has not yet happened.
It's as real as that alien sighting in Jeruselum.
the first vampire sighting was in 0001bc.
I think it has to be the Roswell, NM crash site in 1947.
That was prior to written history so there is no record of the first sighting.
An alien report sighting can be reported to the local media or to NASA. Often times sightings can be found to be a fraud and will be put aside for more important tasks.
The first written sighting of the Northern Lights was reported to be in 2600 B.C
the first sighting was in 1,000,907 BC so yeah that's when it occured.
One of the most well documented UFO sightings occured in 2005 in Xapala, Mexico.
565 AD
Well a Kraken is a mythological creature, so there never was a first sighting of something that didn't exist. But it was seen in Pirate's of the Caribbean ;)
no
Fredrick Fleet