Or at least it is to the astronauts who make an abortive attempt to escort it back to Earth.  (They realize that bringing a Martian organism home is a bad idea in this year’s surprisingly satisfying science fiction-thriller.)

I actually had more fun with this than I expected; the movie is much faster paced and scarier than the trailer made it look.  There are some real surprises and moments of genuine horror here, following a requisite plot setup that is relatively brief.  It’s a really nice monster movie that should please fans of the genre.

I actually didn’t prefer its ending, which is something for which other reviewers are praising it a lot.   I’m disinclined to say more, for fear of spoilers.  The movie’s marketing already spoiled enough.  (The ads infuriatingly show the fate of a main character.)

I will say what the movie is not, however.

One, it’s not a stealth prequel for Sony’s planned 2018 “Spider-Man” spinoff, “Venom” (though that’s such a clever idea, I wish I’d thought of it).

Two, it’s not a ripoff of Ridley Scott’s “Alien” (1979).  Yes, it’s got the same MacGuffin, and some story parallels that I noticed early on.  But I like to think of this as a more grounded contemporary thriller, where “Alien” was a futuristic fantasy creature feature.  Besides, if we criticize every “haunted-house-in-space” movie as an “Alien” imitator, we won’t get more of them.

I’d give this an 8 out of 10, and I’d recommend it.