Salt Water Flows on Mars During The Martian Summer
Δημοσιεύτηκε στις 30 Σεπ 2015
Mysterious
features on slopes hinted for a long time that there could be salt
water presently flowing on Mars during certain seasonal conditions in
certain locations. New findings from NASA's Mars Reconnaissance Orbiter
(MRO) provides the strongest evidence yet that liquid water flows
intermittently on present-day Mars.
Using an imaging spectrometer
on MRO, researchers detected signatures of hydrated minerals on slopes
where mysterious streaks are seen on the Red Planet. These darkish
streaks appear to ebb and flow over time. They darken and appear to flow
down steep slopes during warm seasons, and then fade in cooler seasons.
They appear in several locations on Mars when temperatures are above
minus 10 degrees Fahrenheit (minus 23 Celsius), and disappear at colder
times.
These downhill flows, known as recurring slope lineae
(RSL), often have been described as possibly related to liquid water.
The new findings of hydrated salts on the slopes point to what that
relationship may be to these dark features. The hydrated salts would
lower the freezing point of a liquid brine, just as salt on roads here
on Earth causes ice and snow to melt more rapidly. Scientists say it's
likely a shallow subsurface flow, with enough water wicking to the
surface to explain the darkening.
The spectrometer observations
show signatures of hydrated salts at multiple RSL locations, but only
when the dark features were relatively wide. When the researchers looked
at the same locations and RSL weren't as extensive, they detected no
hydrated salt.
Perchlorates have previously been seen on Mars.
NASA's Phoenix lander and Curiosity rover both found them in the
planet's soil, and some scientists believe that the Viking missions in
the 1970s measured signatures of these salts. However, this study of RSL
detected perchlorates, now in hydrated form, in different areas than
those explored by the landers. This also is the first time perchlorates
have been identified from Mars orbit.
The next question to ask
is, are there any other substances dissolved in this water and, indeed,
what chemical reactions, both inorganic and organic, are allowed to
occur within these flows and, ultimatly, could dormant complex
molecules, either the molecules of life or even life itself, emerge from
these surface liquid water streams? This is yet another valuable piece
of information to place into the vast Martian guidebook assembled by the
scientific efforts of space exploration, with plenty of space left for
future discoveries which are only bound to get more interesting.
features on slopes hinted for a long time that there could be salt
water presently flowing on Mars during certain seasonal conditions in
certain locations. New findings from NASA's Mars Reconnaissance Orbiter
(MRO) provides the strongest evidence yet that liquid water flows
intermittently on present-day Mars.
Using an imaging spectrometer
on MRO, researchers detected signatures of hydrated minerals on slopes
where mysterious streaks are seen on the Red Planet. These darkish
streaks appear to ebb and flow over time. They darken and appear to flow
down steep slopes during warm seasons, and then fade in cooler seasons.
They appear in several locations on Mars when temperatures are above
minus 10 degrees Fahrenheit (minus 23 Celsius), and disappear at colder
times.
These downhill flows, known as recurring slope lineae
(RSL), often have been described as possibly related to liquid water.
The new findings of hydrated salts on the slopes point to what that
relationship may be to these dark features. The hydrated salts would
lower the freezing point of a liquid brine, just as salt on roads here
on Earth causes ice and snow to melt more rapidly. Scientists say it's
likely a shallow subsurface flow, with enough water wicking to the
surface to explain the darkening.
The spectrometer observations
show signatures of hydrated salts at multiple RSL locations, but only
when the dark features were relatively wide. When the researchers looked
at the same locations and RSL weren't as extensive, they detected no
hydrated salt.
Perchlorates have previously been seen on Mars.
NASA's Phoenix lander and Curiosity rover both found them in the
planet's soil, and some scientists believe that the Viking missions in
the 1970s measured signatures of these salts. However, this study of RSL
detected perchlorates, now in hydrated form, in different areas than
those explored by the landers. This also is the first time perchlorates
have been identified from Mars orbit.
The next question to ask
is, are there any other substances dissolved in this water and, indeed,
what chemical reactions, both inorganic and organic, are allowed to
occur within these flows and, ultimatly, could dormant complex
molecules, either the molecules of life or even life itself, emerge from
these surface liquid water streams? This is yet another valuable piece
of information to place into the vast Martian guidebook assembled by the
scientific efforts of space exploration, with plenty of space left for
future discoveries which are only bound to get more interesting.
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