Home' Trinidad and Tobago Guardian : March 18th 2014 Contents A34
Guardian www.guardian.co.tt Tuesday, March 18, 2014
Detailed maps of Mercury s
cliffs and ditches show the solar
system s innermost and smallest
planet Mercury has lost much
more real estate due to cooling
over four billion years than sci-
entists thought, according to a
report published on Sunday.
Cooling of Mercury s massive
iron core has pared about nine
miles from the planet s diameter,
more than twice as much as pre-
"When you look at the actual
number, it s really pityingly small,
compared to the size of a planet.
But it doesn t need to change very
much to have some effect," said
planetary scientist Paul Byrne,
with the Carnegie Institution s
Department of Terrestrial Mag-
Scientists studied more than
5,900 surface features, including
cliff-like scarps and wrinkle
ridges, to calculate how much
Mercury has condensed.
Unlike Earth, which as several
plates of crust, Mercury has just
one rigid, rocky layer which bears
telltale cliffs and chasms caused
by global contraction.
The measurements, made with
NASA s Mercury-orbiting Mes-
senger spacecraft, match com-
puter model predictions, which
scientists use to determine the
planet s inner composition, chem-
istry and structure.
"An awful lot of a planet s
processes are driven by its heat
loss---that s a primary thing that
drives a planet s evolution," Byrne
said. "We didn t set out to prove
the models right, but it turns out
this number is exactly what the
models have been predicting for
Previous maps of Mercury s
surface map date back to the mid-
1970s. NASA s Mariner 10 space-
craft made three flybys of the
planet, imaging about 45 per cent
of its surface.
That data indicated Mercury
had lost 1.2 to 3 miles in diameter,
a finding that clashed with sci-
entists heat dissipation models
for the planet.
In addition to learning more
about how Mercury evolved, the
discovery has implications for
assessing the compositions of
planets beyond the solar system.
"It may be that Mercury is an
archetypal example of what a
planet does and how it behaves
as it has cooled in time," Byrne
The research is published in the
journal Nature Geoscience.
New maps show smallest
planet Mercury even smaller
Skin-tight space suits
'support astronauts' bones
Scientists have developed a
skin-tight spacesuit to try to stop
astronauts spines expanding.
They hope the lightweight elas-
tic material will mimic the force
of gravity on the body.
Astronauts spines can lengthen
by up to 7cm (3in) with no gravity
to compress the bones, painfully
pulling on muscles and nerves.
Using designs by MIT, scientists
at King s College London are
refining the tailor-made suits for
testing in space.
As astronauts bones and mus-
cles do less work to keep them
upright once they experience
weightlessness, they can also start
to waste away.
All these factors can make them
more likely to experience long-
term back and other health prob-
lems on return to Earth.
The researchers say these issues
are likely to pose an even greater
challenge on extended missions
such as proposed journeys to
Italian and American tailors
worked with the international
team of scientists to make skin
suits composed of multiple layers
of elastic material.
The material is woven in two
directions, in a way that gradually
produces more tension, squeezing
the body from shoulder to feet.
European Space Agency astro-
naut Andreas Mogensen will be
the first to wear the suit in space
during his mission in 2015.
And Dr Green says if it is given
it the nod of approval on that
mission, UK astronaut Tim Peake
could wear the suit on his mission
to the international space station
later that year.
Making skin suits to help astro-
nauts counteract microgravity is
not new---Russian scientists came
up with the Pingvin or penguin
suit in 1991.
But scientists have been
attempting to make new suits to
better mimic gravity and that are
more comfortable to wear.
Like the Pingvin suits, Dr Green
hopes the new skin suit may have
therapeutic uses on Earth.
Modified Pingvin suits have
been used to help support and
maintain the posture and limbs
of people with movement prob-
lems, including children with
A 2008 photo of shrinking Mercury from Nasa. The planet is 4,880km wide and is dominated by its giant iron
core. PHOTO COURTESY NASA
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