A condom that has been used, and after sex, the bloke leans out of the window, (or aims at a place with people) and chucks it at them. Similar to the normal nerf ball, as in it is weighty at one end, and flys like hell! Appropriate scoring can be made for accuracy and distance of throw.

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.