[ white noise ] [ music ] Since the 1960's,
scientists have suspected that frozen water
could survive in permanently shadowed craters
at the Moon's poles.
Both hydrogen and oxygen could be trapped
within the lunar soil.
So to find water on the Moon, scientists are
looking for indications of hydrogen using
the Lunar Reconnaissance Orbiter's LEND neutron
detector.
By observing the interaction of neutrons with
the lunar soil, scientists can interpret how
much hydrogen is likely to be present.
In order to make a detailed interpretation,
however, LEND needs to observe a large number
of neutrons.
Because LRO is constantly moving, LEND is
never over one place long enough to count
many neutrons.
So, to make a detailed interpretation of neutron
flux, scientists add together many measurements
from many orbits.
With each orbit LEND's dataset gets larger
and its picture of neutron flux continually
improves over time.
The dark blue regions in this visualization
are places on the south pole of the Moon with
a suppressed flux of neutrons because of their
interaction of hydrogen.
These areas strongly suggest the presence
of water frozen within the soil.
While previous lunar missions have observed
indications of hydrogen at the Moon's south
pole, the LEND measurements for the first
time pinpoint where hydrogen, and thus water,
is likely to exist.
By combining years of LEND data, scientists
see accumulating evidence that there is water
on the Moon.
And as LRO continues to return data, our picture
of the Moon and its water will continue to
get better in the years ahead.
[ music, sound effect ]
