1. When your friends or family go out, and they post pictures on Facebook or Instagram, but you don't seem to be in any of them. And you realize, you weren't invited.

You say, "thanks for the invite, bitches." Or just, "tftib." The "b" can also stand for the singular word, "bitch."

This is a variant of "tfti" that is to be used when you were bored at home the whole day and would have liked to do something nice because it is summer. And you would normally be ok when people don't invite you because you're independent like that, but this time, you're not happy. Because you really wanted to go out, have fun, and sing "Call Me Maybe" and One Direction in the car.

2. Same as above, but you aren't sarcastic this time. That's because you would rather go to an American Idol audition, wait for 6 hours, and be humiliated rather than hanging out with losers who can't please you even if they tried.

The safeguarding of Earth and other worlds from biological cross-contamination (i.e. billionaires with too much time on their hands).

Also known as “planetary protection.” Planetary protection / quarantine “reflects both the unknown nature of the space environment and the desire of the scientific community to preserve the pristine nature of celestial bodies until they can be studied in detail.”

There are two types of interplanetary contamination. Forward contamination is the transfer of viable organisms from Earth to another celestial body. Back contamination is the transfer of extraterrestrial organisms, if such exist, back to the Earth's biosphere.