  The origin, distribution, depth and volume of lunar volatiles remain open
questions. One of the possible sources of Moon's volatiles is their volcanic
outgassing during the peak of lunar volcanic activity ~3.5 Ga. This same
outgassing would also produce a tenuous transient atmosphere which would
promote the delivery of volatiles from the volcanic sources to the polar cold
traps. Though such an atmosphere could have played an important role in the
evolution of the Moon, little is known about it due to high uncertainty level
in the mechanisms involved. The only reliable proxy for the ancient lunar
atmosphere are the primordial volatiles deposited by it, which are expected to
be preserved in the polar cold traps, and could be studied through sample
return. In this white paper we therefore advocate that a volatile sample return
from the Moon's polar cold traps should be a fundamental part of the Artemis
program.
