Today (July 2) is officially World UFO Day -- which means you're probably already outside with a telescope, hoping for a repeat of the 1947 Roswell "incident" if you're into that sort of thing. Here at MTV News we're more of what you might call "indoor kids," which is why we've foregone looking at the sky in favor of researching pictures of the hottest aliens in television and movie history.

Below we've compiled a list of our 21 favorite hot aliens, but just know that there are rules -- future-humans who happen to be from alien planets (like, say, Alderaan) are not included, but alien life forms hiding out in human bodies are fair game. Geronimo!

1. Thomas Jerome Newton, "The Man Who Fell To Earth"

It's David Bowie, you guys.

2. Sil, "Species"

Your boyfriend's favorite alien, at least until...

3. Leeloo, "The Fifth Element"

The alien who spawned a zillion Comic Con costumes.

4. Diva Plavalaguna, "The Fifth Element"

That voice! That body! That... hair?

5. Neytiri, "Avatar" (And Gamora, "Guardians of the Galaxy")

Props to Zoe Saldana for being the first person to be typecast as a hot alien. We haven't seen her kick ass as Gamora yet, but come on -- you know it's going to be sexy.

6. Thor, "Thor" (And "Thor 2", "The Avengers"...)

Those. Arms.

7. Loki, "Thor" (And "Thor 2", "The Avengers"...)

Don't worry, Internet -- we'd never forget your (and our) alien boyfriend.

8. Deanna Troi, "Star Trek: The Next Generation"

Half-human, half-Betazoid, full-on hottie.

9. The Tenth And Eleventh Doctors, "Doctor Who"

Two beautiful faces, one Time Lord.

10. Diana, "V"

Supreme Commander of Alien Hotness.

11. Serleena, "Men In Black 2"

Turns out aliens have really great taste in lingerie.

12. Threes, Sixes, And Eights, "Battlestar Galactica"

Beautiful, intelligent, tough, and savvy enough to realize when their cohorts were full of crap.

13. Aayla Secura, "Star Wars Episode III: Revenge of the Sith"

This Twi'lek serves as more proof that blue looks good on everyone.

14. Spock, "Stark Trek"

Nimoy was the original, but Quinto landed Nyota Uhura.

15. Superman, "Man of Steel"

Okay, so we didn't love the movie, but that doesn't mean that Henry Cavill didn't wear the Super-suit better than anyone.

16. Celeste, "My Stepmother Is An Alien"

Step-MILF.

17. Starman, "Starman"

Soooo romantic.

18. Princess Aura, "Flash Gordon"

Makes being the daughter of an evil emperor look easy. And hot.

19. Marta, "Star Trek: The Original Series"

No man can resist an Orion woman!

20. Mac, "Earth Girls Are Easy"

Years before Goldblum fought aliens (or, sorry, "gave them a cold") in "Independence Day," he was one in "Earth Girls Are Easy."

21. Edgar, "Men In Black"

Don't judge.