Alien invasion is alive and well in Hollywood this season, given Men in Black III, Battleship, and Prometheus, which opens June 8 in the U.S., IEEE Spectrum Tech Talk reports.

Cue Seth Shostak, senior astronomer with the SETI Institute, who offers five points about aliens that don’t cut it in Hollywood:

1. Your great-great-grandma was probably not from outer space.

“I get emails every week saying that Homo sapiens are the result of alien intervention. I’m not sure why aliens would be interested in producing us.  I think people like to think we’re special. But isn’t that what got Galileo and Copernicus into trouble – questioning how special we were? But if we’re just another duck in the road, it’s not very exciting.”

2. If aliens come, we’re probably toast.

“Whoever takes the trouble to come visit us is probably a more aggressive personality. And if they have the technology to come here, the idea that we can take them on is like Napoleon taking on U.S. Air Force. We’re not going to be able to defend ourselves very well. But if I wanted that to be correct, it would be a very short movie.”

3. They won’t catch our colds.

“Alien life forms wouldn’t come here only to be done in by our bacteria, unless they were related biochemically to humans. Bacteria would have to be able to interact with their biochemistry to be dangerous, and their ability to do that is far from a sure thing.”

4. Aliens don’t look like Screen Actors Guild members.

“Thanks to computer animation, we now have more variety of aliens in films, but they’re still soft and squishy—and big on mucus. Chances are, the first invaders will be some sort of artificially intelligent machinery. But in films, even machinery needs to look like biology, otherwise actors would be talking to a box.”

5. Nobody’s getting lucky.

“The idea that they’ve come for breeding purposes is more akin to wishful thinking by members of the audience who don’t have good social lives. Think about how well we breed with other species on Earth, and they have DNA. It would be like trying to breed with an oak tree.”