Michael S. Heiser's words:
VIDEO 3: a video of me [Michael S. Heiser] searching the ETCSL for the word “Anunnaki”
ETCSL = Electronic Text Corpus of Sumerian Literature
viewers can see for themselves how to search for the term “Anunnaki” in Sumerian — and they’ll see that there are no texts that have them inhabiting Nibiru (or riding in in [likely meant "space ships"]) or that they are extraterrestrials.
Watch Michael's video: Michael S. Heiser video searching the ETCSL for "Anunnaki"
As the title says, Zecharia Sitchin just made it up about the Anunnaki, etc.
Sitchin's methods are extremely common in all of what is called "New Age." I have yet to research one main person involved in the New Age Movement, Theosophy, or anything of the sort where the results of that research has left me with any doubts as to the utter bogusness of their most supposedly definitive claims. Their final claims turn up in every case to have been built upon very, very wild assumptions. If you pay attention to Sitchin, for one, you will even hear him say "maybe" about things that he ends up turning into definitives but without having done any intervening explaining or having supplied any additional so-called evidence.
I also want to add that I have not read all of Michael S. Heiser's work. I will not say at this point the degree to which I might agree with him on other matters. I will say though that I do severely discount (even entirely dismiss) everything popularly posited by "Zecharia Sitchin" versus Michael S. Heiser's basic work on the subject.