NASA has this "planetary protection" scheme. But it seems to apply to non-planets, like Enceladus and Europa. Thus Galileo and Cassini probes are crashed into their gas giants. How does this add up? Is there a misnamed everything-in-space-"protection" policy?
-
1$\begingroup$ Perhaps only a misnomer in the case of comets. Enceladus and Europa are both planetary mass objects, and dwarf planets and asteroids are either planetoids or "minor planets". $\endgroup$– called2voyage ♦Commented Jun 7, 2017 at 14:18
-
$\begingroup$ At a base level, "planet" in the loose sense is generally understood to refer to the junk that goes around a star. The IAU definition of planet is the strict sense. It is in that sense that all those other objects are not planets. The IAU is trying to move away from the loose meaning of "planet", but language is a tough beast. $\endgroup$– called2voyage ♦Commented Jun 7, 2017 at 14:45
3 Answers
"Planetary protection" is a minor misnomer. From NASA:
Planetary protection is the term given to the practice of protecting solar system bodies (i.e., planets, moons, comets, and asteroids)
"Planetary" is simply an easier word to manage than "celestial-body-related".
Such misnomers are extremely common in all fields.
The term "planetary protection" predates our current understanding of our solar system. Since 1958, we've made discoveries that led scientists to consider the possibility of life existing on moons like Europa.
So the responsibilities of the Office of Planetary Protection expanded, but the name stayed the same.
Planets, moons, comets it does not really matter. The goal is to protect an environment where life could have developed or might develop. The name may not be entirely well chosen for accuracy as opposed to emotional impact.
-
$\begingroup$ But how well defined is the purpose of "planetary protection" given their nomenclature? Do they know what to protect, you know. from life? Or is the purpose really just to make an emotional impact as you say. $\endgroup$ Commented Jun 7, 2017 at 14:35
-
$\begingroup$ "protect life wherever it may have occurred" is plenty well-defined. $\endgroup$– HobbesCommented Jun 7, 2017 at 17:56