If you have some proof of astroturfing you should write a blog and then share on hn, it might make for a very good post here. otherwise it feels wildly inappropriate (not to mention incredibly unlikely that they would spend marketing money on astroturfing here of all places). Andy Weir has written some books that are incredibly successful in the tech industry circles with Hail Mary being the current most popular if not slightly under The Martian, chances are there's just going to be a lot of talk about it. But even if there is astroturfing, telling people to not watch the movie in a thread where someone is showing off their space photography is inappropriate and misplaced.