Uh, no.
In his very first book, "The Twelfth Planet", Sitchin claims that a planet Nibiru is in a 3600 year orbit around the Earth. One contemporary reviewer pointed out that Sitchin apparently sync'ed this such that the most recent pass of the planet was in the late centuries B.C., an event for which there is no testimony. The reviewer also pointed out that the supposed information from the aliens regarding the extent of the orbit was incompatible with Kepler's laws.
I was just kidding. Actually, I have a lot of fun with Sitchin's books. A real enigma. He's nothing less than an expert on the early civilizations of Sumeria, Babylon, etc; especially adept at reading the scrolls and understanding the language of those civilizations and then totally blows all credibility with his 12th planet nonsense. I suppose it's because playing to the Von Danikin crowd sells a heck of a lot more books than playing straight. If you care to read just one of his books that has a lot of interesting intellectual insights on the origins of civilization similar to the stuff you post here, I'd recommend "When Time Began" but fair warning, you still have to gloss over the 12th planet spacemen stuff to get to the good parts.