A teaser pony prevents the mare from damaging a prize stallion. The teaser is led out to the pasture. If the mare is violently unwilling, there’s no danger of injuring a horse whose bloodlines make him valuable breeding stock. If the mare presents, the teaser is led away, and the stud is brought in to mate with the stare. So basically is a "test horse" used to give other male horses boners, and a test bang. It can act as a great insult.

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.