Hah, I love how many of you think we're all aliens.
The "races" are nothing more than genetic modification. Lunarans (not lunarians) are designed to live on the moon, and have light, thin, somewhat frail bodies, and they kinda remind me of the "grey aliens" of your time, except white, and FAR more human in the face.
Martians are merely designed for life on Mars, and frankly, look like little black goblins to me.
Helenes like me, I'm sad to say were the first attempt at reprogenetics, and are merely aesthetic. We're basically designed to be pretty (for women) or handsome (for men) although the men look more like tacky Greek statues than "handsome" in my opinion. Designed for porn and similar aesthetic endeavors (acting, funny as it sounds), mostly.
I think the best way to look at a Helene, at least in the male sense, is Urien from a game called Street Fighter 3, which I'm fairly sure is around in your time.
I'm much wider, but it's generally the same.