Yahoo – AFP,
Laurence COUSTAL, July 24, 2017
 |
| Scientists have found evidence of widespread water in the Moon's interior (AFP Photo/PASCAL GUYOT) |
Paris (AFP)
- The Moon, long thought to be a dry, inhospitable orb, hosts surprisingly
large sub-surface water reserves, which one day may quench the thirst of lunar
explorers from Earth, scientists said Monday.
"We
found the signature of the lunar interior water globally using satellite
data," Shuai Li, co-author of a study by scientists at Brown University in
the United States, told AFP.
"Such
water can be used as in situ resources for future exploration," said Li, a
postdoctoral researcher at the University of Hawaii and Brown Ph.D graduate.
Li noted
scientists had believed the Moon to be "bone dry" until about a
decade ago, when scientists found evidence of water -- an essential ingredient
for life -- in pebble-like beads brought back by Apollo missions.
The Brown
findings show numerous volcanic deposits distributed across the surface of the
Moon contain "unusually high amounts of trapped water" compared with
surrounding terrain.
They say
discovery of water in the ancient deposits, which are believed to consist of
glass beads formed by the explosive eruption of magma from beneath the Moon's
surface, boosts the idea that the lunar mantle is surprisingly water-rich.
"The
key question is whether those Apollo samples represent the bulk conditions of
the lunar interior or instead represent unusual or perhaps anomalous water-rich
regions within an otherwise 'dry' mantle," said Ralph Milliken, lead
author of the new research, published in the Nature Geoscience journal on
Monday.
"The
distribution of these water-rich deposits is the key thing," Milliken
said. "They're spread across the surface, which tells us that the water
found in the Apollo samples isn’t a one-off," he added.
"By
looking at the orbital data, we can examine the large pyroclastic deposits on
the Moon that were never sampled by the Apollo or (Soviet) Luna missions,"
said the associate professor at Brown's Department of Earth, Environmental and
Planetary Sciences.
"The
fact that nearly all of them exhibit signatures of water suggests that the
Apollo samples are not anomalous, so it may be that the bulk interior of the
Moon is wet."
Scientists
believe the Moon formed from debris left behind after an object about the size
of Mars slammed into the Earth early in solar system history.
They had
assumed it was unlikely that any of the hydrogen needed to form water could
have survived the heat of that impact.
"The
growing evidence for water inside the Moon suggests that water did somehow
survive, or that it was brought in shortly after the impact by asteroids or
comets before the Moon had completely solidified," said Li.
The
volcanic beads contain only tiny amounts of water but the deposits are large
and the water could potentially be extracted.
"Other
studies have suggested the presence of water ice in shadowed regions at the
lunar poles, but the pyroclastic deposits are at locations that may be easier
to access," said Li.
"Anything
that helps save future lunar explorers from having to bring lots of water from
home is a big step forward, and our results suggest a new alternative."
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