For this chain-of-thought reasoning and answer, what was the question?
To answer the question, consider the following: Several novelizations of each of the six films and some comic books as well as original canonical novels based on the franchise have been released.
A: six
Q: Several novelizations of each of the six films and some comic books as well as original canonical novels based on the franchise have been released. The original novels include Alien: Out of the Shadows, Alien: Sea of Sorrows, Alien: River of Pain, marketed as the Canonical Alien Trilogy and the short story collection Aliens: Bug Hunt. Out of the Shadows and River of Pain were adapted into audio dramas in 2016 & 2017 respectively released on the Alien Day of the respective year. Alan Dean Foster published Alien: Covenant -- Origins, a novel set between the events of Prometheus and Alien: Covenant

Based on this passage, how many movies are in the aliens series?