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The
basaltic fragments, similar to most of the Earth's volcanic
rock, are the remains of the moon's volcanic past, with studies
showing evidence of eruptions up until 1.5 billion to 2 billion
years ago.
By examining samples from the moon, as well as Mars and the
asteroid Vesta, scientists are comparing how rocks are formed
under different gravitational conditions; specifically, how
gravity affected the magma within rocky bodies billions of years
ago.
"At the moment we are facing a disconnect in volcanology where
we can monitor what's happening in a volcano in the present but
it's very difficult to see the future because we have no
reference to the past," Matt Pankhurst of the Canarian
Volcanlogical Institute (INVOLCAN) in Tenerife, leader of the
study team, told Reuters.
"We're looking at moon rocks because they have something very
special in that they were formed in a lower gravity environment
and that changes how the crystals and the melt behave with one
another as they're forming. So studies like this give us a
baseline to understand processes that happen at terrestrial
gravity on earth," he said.
For the study, NASA has loaned 18 lunar samples that are
normally kept under lock and key at Johnson Space Center (JSC)
in Houston, Texas.
Between 1969 and 1972 over 2,000 separate samples were collected
by the six Apollo missions to land on the moon; amounting to 382
kilograms (842 pounds) of rocks, pebbles and dust from the lunar
surface.
Ryan Zeigler, NASA's Apollo sample curator, said the samples
used in the study are from the Apollo 12 and 15 missions, some
of which came from a wide area of the lunar surface.
"Apollo 15 was the first mission where they had the rover (space
exploration vehicle) so they were able to traverse a larger
area. So they were able to visit a basaltic feature called a
rille; basically an old collapsed lava tube. And so this is from
a volcanic area, not unlike Hawaii," Zeigler, holding a fragment
of moon rock encased in resin, told Reuters at the Diamond Light
Source institute in Britain, where the research is being carried
out.
Scientists in Tenerife, the United States and Britain are
conducting the study.
Diamond Light Source, near Oxford, is Britain's national
synchrotron science facility that produces intense beams of
light.
Here electrons are accelerated to near light speeds until they
emit light 10 billion times brighter than the sun, then directed
into laboratories in 'beamlines' which allow scientists to study
minute specimens using x-ray beams in extreme detail without
damaging them.
Pankhurst said it allows them to study "the individual histories
of individual crystals" within the rocks.
"We're looking inside the sample and looking at in ways that
we've never been able to see before," he said, while carefully
placing a sample into the machine.
"If you want to understand how the volcanoes on Earth are going
to erupt and in what timescale they're going to erupt on,
studying rocks from other planets will help you actually learn
about that more," said Zeigler.
The study, funded by the UK government and research charity the
Wellcome Trust, could also aid our understanding of lunar and
planetary formation.
"Understanding how volcanism works on other planets lets us
understand how the whole solar system formed. So if we want to
know how we went from a giant ball of dust to nine planets
orbiting around the sun... this is how we're going to do it;
studies like this, on rocks like this," Zeigler said.
(Reporting by Matthew Stock; Editing by Susan Fenton)
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