Speaking strictly as a TV-show-only watcher, I wasn’t surprised (or shocked for better term) to be honest.

Immortal seemed wayyy too good and without flaws. Despite his superiority complex, he’s just as infallible to normal human vices as everyone else (such as Rex). Really interested in the direction this is going.

Nah the new one isn’t evil, he was just nervous about being discovered as a Martian. Then he sees the news story about Martian Man and wants to be a hero too.

There’s a scene that shows the actual dead astronaut, and that one is taken over by the parasite alien. Also shows it leading the other parasites, building a ship, and starting to come to earth.