Heartless,
Having no emotions,

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.

1. Cold (adj.) - Being low in temperature; without warmth; lacking heat.

2. Cold (adj.) - Being without emotion, remorse, regret, empathy; heartless

3. Cold ( adj.) - Used to describe someone who looks good; (In this sense, the word may mean the same as hot.

Somebody who looks good.

what a girl says she is when she wants to snuggle :

Better than cool
To be cooler than cool
The coolest level of cool