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Europa’s ET Life Hotspots Identified –NASA
2 Votes
April 15, 2013
Europa’s ET Life Hotspots Identified –NASA
New analysis of observations made more than a decade ago by NASA’s Galileo mission to Jupiter helps identify places where Jupiter’s moon Europa
exposes material churned up from inside the moon. “We have found the
regions where charged electrons and ions striking the surface would have
done the most, and the least, chemical processing of materials emplaced
at the surface from the interior ocean,” said J. Brad Dalton of NASA’s Jet Propulsion Laboratory, lead author of the report published recently in the journal Planetary and Space Science.
“That tells us where to look for materials representing the most
pristine ocean composition, which would be the best places to target
with a lander or study with an orbiter.”
Europa is about the size of Earth’s moon and, like our moon, keeps
the same side toward the planet it orbits. Picture a car driving in
circles around a mountain with its left-side windows always facing the
mountain.
Europa’s orbit around Jupiter is filled with charged, energetic
particles tied to Jupiter’s powerful magnetic field. Besides electrons,
these particles include ions of sulfur and oxygen originating from
volcanic eruptions on Io, a neighboring moon. The magnetic field
carrying these energetic particles sweeps around Jupiter faster than
Europa orbits Jupiter, in the same direction: about 10 hours per circuit
for the magnetic field versus about 3.6 days for Europa’s orbit.
So, instead of our mountain-circling car getting bugs on the front
windshield, the bugs are plastered on the back of the car by a “wind”
from behind going nearly nine times faster than the car. Europa has a
“leading hemisphere” in front and a “trailing hemisphere” in back.
Earlier studies had found more sulfuric acid being produced toward
the center of the trailing hemisphere than elsewhere on Europa’s
surface, interpreted as resulting from chemistry driven by sulfur ions
bombarding the icy surface. Dalton and his co-authors at JPL and at Johns Hopkins University Applied Physics Laboratory,
Laurel, Md., examined data from observations by Galileo’s near infrared
mapping spectrometer of five widely distributed areas of Europa’s
surface.
The spectra of reflected light from frozen material on the surface
enabled them to distinguish between relatively pristine water and
sulfate hydrates. These included magnesium and sodium sulfate salt
hydrates, and hydrated sulfuric acid. They compared the distributions of
these substances with models of how the influxes of energetic electrons
and of sulfur and oxygen ions are distributed around the surface of
Europa. The concentration of frozen sulfuric acid on the surface varies
greatly, they found. It ranges from undetectable levels near the center
of the leading hemisphere, to more than half of the surface materials
near the center of the heavily bombarded trailing hemisphere. The
concentration was closely related to the amount of electrons and sulfur
ions striking the surface.
“The close correlation of electron and ion fluxes with the sulfuric
acid hydrate concentrations indicates that the surface chemistry is
affected by these charged particles,” says Dalton. “If you are
interested in the composition and habitability of the interior ocean,
the best places to study would be the parts of the leading hemisphere we
have identified as receiving the fewest electrons and having the lowest
sulfuric acid concentrations.”
Surface deposits in these areas are most likely to preserve the
original chemical compounds that erupted from the interior. Dalton
suggests that any future spacecraft missions to Europa should target
these deposits for study from orbit, or even attempt to land there. *
“The darkest material, on the trailing hemisphere, is probably the
result of externally-driven chemical processing, with little of the
original oceanic material intact,” said Dalton. “While investigating the
products of surface chemistry driven by charged particles is still
interesting from a scientific standpoint, there is a strong push within
the community to characterize the contents of the ocean and determine
whether it could support life. These kinds of places just might be the
windows that allow us to do that.”
The graphic below of Jupiter’s moon Europa maps a relationship
between the amount of energy deposited onto the moon from
charged-particle bombardment and the chemical contents of ice deposits
on the surface in five areas of the moon (labeled A through E).
Journal reference: Planetary and Space Science
The Daily Galaxy via JPL/NASA
Europa’s ET Life Hotspots Identified –NASA.
Thanks to: http://2012indyinfo.com
2 Votes
April 15, 2013
Europa’s ET Life Hotspots Identified –NASA
New analysis of observations made more than a decade ago by NASA’s Galileo mission to Jupiter helps identify places where Jupiter’s moon Europa
exposes material churned up from inside the moon. “We have found the
regions where charged electrons and ions striking the surface would have
done the most, and the least, chemical processing of materials emplaced
at the surface from the interior ocean,” said J. Brad Dalton of NASA’s Jet Propulsion Laboratory, lead author of the report published recently in the journal Planetary and Space Science.
“That tells us where to look for materials representing the most
pristine ocean composition, which would be the best places to target
with a lander or study with an orbiter.”
Europa is about the size of Earth’s moon and, like our moon, keeps
the same side toward the planet it orbits. Picture a car driving in
circles around a mountain with its left-side windows always facing the
mountain.
Europa’s orbit around Jupiter is filled with charged, energetic
particles tied to Jupiter’s powerful magnetic field. Besides electrons,
these particles include ions of sulfur and oxygen originating from
volcanic eruptions on Io, a neighboring moon. The magnetic field
carrying these energetic particles sweeps around Jupiter faster than
Europa orbits Jupiter, in the same direction: about 10 hours per circuit
for the magnetic field versus about 3.6 days for Europa’s orbit.
So, instead of our mountain-circling car getting bugs on the front
windshield, the bugs are plastered on the back of the car by a “wind”
from behind going nearly nine times faster than the car. Europa has a
“leading hemisphere” in front and a “trailing hemisphere” in back.
Earlier studies had found more sulfuric acid being produced toward
the center of the trailing hemisphere than elsewhere on Europa’s
surface, interpreted as resulting from chemistry driven by sulfur ions
bombarding the icy surface. Dalton and his co-authors at JPL and at Johns Hopkins University Applied Physics Laboratory,
Laurel, Md., examined data from observations by Galileo’s near infrared
mapping spectrometer of five widely distributed areas of Europa’s
surface.
The spectra of reflected light from frozen material on the surface
enabled them to distinguish between relatively pristine water and
sulfate hydrates. These included magnesium and sodium sulfate salt
hydrates, and hydrated sulfuric acid. They compared the distributions of
these substances with models of how the influxes of energetic electrons
and of sulfur and oxygen ions are distributed around the surface of
Europa. The concentration of frozen sulfuric acid on the surface varies
greatly, they found. It ranges from undetectable levels near the center
of the leading hemisphere, to more than half of the surface materials
near the center of the heavily bombarded trailing hemisphere. The
concentration was closely related to the amount of electrons and sulfur
ions striking the surface.
“The close correlation of electron and ion fluxes with the sulfuric
acid hydrate concentrations indicates that the surface chemistry is
affected by these charged particles,” says Dalton. “If you are
interested in the composition and habitability of the interior ocean,
the best places to study would be the parts of the leading hemisphere we
have identified as receiving the fewest electrons and having the lowest
sulfuric acid concentrations.”
Surface deposits in these areas are most likely to preserve the
original chemical compounds that erupted from the interior. Dalton
suggests that any future spacecraft missions to Europa should target
these deposits for study from orbit, or even attempt to land there. *
“The darkest material, on the trailing hemisphere, is probably the
result of externally-driven chemical processing, with little of the
original oceanic material intact,” said Dalton. “While investigating the
products of surface chemistry driven by charged particles is still
interesting from a scientific standpoint, there is a strong push within
the community to characterize the contents of the ocean and determine
whether it could support life. These kinds of places just might be the
windows that allow us to do that.”
The graphic below of Jupiter’s moon Europa maps a relationship
between the amount of energy deposited onto the moon from
charged-particle bombardment and the chemical contents of ice deposits
on the surface in five areas of the moon (labeled A through E).
Journal reference: Planetary and Space Science
The Daily Galaxy via JPL/NASA
Europa’s ET Life Hotspots Identified –NASA.
Thanks to: http://2012indyinfo.com
