Phil Plait
Notes
Phil Plait (born 1964), American astronomer and science writer, "the Bad Astronomer". Bad Astronomy (2002) remains the best single refutation of the Moon landing hoax claims and of a great deal of other astronomical nonsense, including flat Earth claims. His rule for sceptics, "don't be a dick", is good advice I do not always follow.
Wikipedia: https://en.wikipedia.org/wiki/Phil_Plait