Warning: Controversial. May be offensive to "Fundamentalists".
This book starts a series of works by one contemporary author who, as a young schoolboy studying the Old Testament in Hebrew, became obsessed with the word Nefilim and went on through life discovering the basis of a hypothesis on Man's origins considered by the UPI as "the most astonishing of all".
If you have the slightest suspicion that extraterrestrials may indeed exist, Jewish scholar and best-selling author Zecharia Sitchin can prove you right. Presenting an extensive body of evidence amassed over years of meticulous research, he has ably established a strong case which is "brilliant and explosive".
Arguing that the word Nefilim literally means "those who were cast down" and not "giants", Sitchin pursued a life's work of discovering who these extraterrestrials were.
Man, it seems, is not native to this planet. All life forms on Earth contain too little of the chemical elements that abound here but more of those that are plentiful in outer space. Then, from 3800 B.C. and every 3,600 years backwards, there appears to have been events that uplifted Mankind from decadence into a cutural revival of sorts as if some unseen mentor periodically returned.
It is estimated that the first human civilization known to us came about circa 3800 B.C. It seems that there is no known precursor, no data of a slow series of developments that led to it. This is the Sumerian civilization, amazingly highly-developed even by present standards. They had a written language, a manner of printing, advanced pottery, kiln, uses for fossil oil, metallurgy, mathematics, astronomy, chemistry, medicine, a bicameral assembly...and so much more - enough to raise the question if they had the time to learn all by themselves.
Strengthening Sitchin's arguments are the recorded Sumerian claims that they learned what they knew from the ilu ("lofty ones"). In the Akkadian language, the term is Anunnaki or "those who from heaven to earth came", not much different from Nefilim.
The Anunnaki, it appears, came from a roving comet-like planet called Nibiru. It comes around to and through our Solar System every 3,600 years. A long long time ago, in events now echoed by the first few verses of the Book of Genesis, Nibiru came through with collisions and near-collisions that shaped our Solar System as it is today.
The ancients referred to this planet as "The Lord", naming it after their foremost deity. Terrifying was "The Lord's Day" as it came with meteor showers and great earthquakes caused by gravitational pulls. Counting all nine planets, plus the Sun and the Moon, Nibiru became the 12th planet of our Solar System. Then each was assigned a corresponding deity, the top 12 leaders of the Anunnaki. Hence, the possible origin of the sacred number 12.
When they landed, why they landed, the events leading to the fashioning of the "adamu", the establishment of a headquarters called the "Edin", the seeming immortality of the Anunnaki...the book does better justice to itself. This and all related works are available in a special store - Brethren of Yeshua at Amazon.