What is Planetary Protection? Planetary protection is the term
given to the practice of protecting solar system bodies (i.e.,
planets, moons, comets, and asteroids) from contamination by
Earth life, and protecting Earth from possible life forms that
may be returned from other solar system bodies. Planetary
protection is essential for several important reasons: to
preserve our ability to study other worlds as they exist in
their natural states; to avoid contamination that would obscure
our ability to find life elsewhere — if it exists; and to ensure
that we take prudent precautions to protect Earth’s biosphere in
case it does. Typically, planetary protection is divided into
two major components: forward contamination, which refers to the
biological contamination of explored solar system bodies; and
backward contamination, which refers to the biological
contamination of Earth as a result of returned extraterrestrial
samples. NASA Planetary Protection Policy NASA maintains a
planetary protection policy that is d