Do we have an intact
ocean on Mars? I think that we
should. However once it froze, it became a layer of sediment
and in the low gravity lost whatever plasticity that we take for granted on
Earth. This sedimentary layer was then
steadily covered by windblown sediments built up to this day.
The existence of
sublimated water on the poles certainly tells us that a source reservoir
exists.
All this makes establishing
a human presence on Mars far more practical. Assuming an excellent energy
source, it is no trick to drill for water and to bring it to surface to support
greenhouses or even to build underground in order to avoid radiation.
In practice, this means
that huge human population can be now established and sustained rather easily
through accessing this water and building protective artificial atmospheric
environments.
In other words, it did
not all evaporate into space as some have suggested.
Evidence of Martian
ocean grows
The
Aeolis Riviera is the strongest evidence thus far of a large amount of water on
Mars.
Ellen
Miller | Sunday, July 21, 2013
By
using the Mars rovers as well as high-tech orbital data, scientists have been
able to make significant progress in their search for evidence of water on
Mars. Water is key to life, hence the intense search, but previously it was
difficult to say whether water existed in any significant amount on the Martian
planet. Now, Caltech scientists believe that they have found evidence of a
river delta that flowed into a large body of water on the planet. The Aeolis
Riviera is the strongest evidence thus far of a large amount of water on Mars.
The
Caltech team utilized high-resolution images from NASA’s Mars
Reconnaissance Orbiter’s High-Resolution Imaging Science Experiment (HiRISE)
camera to examine the surface of the planet closely. On the Aeolis Dorsa, where
the Curiosity rover is currently exploring and searching for clues to the past,
the team observed what could be a river delta leading into a large depression.
Scientists
believe that the northern hemisphere of Mars was largely covered by water,
as it is at a lower elevation than the southern hemisphere. However, time
has weathered the surface, making a large body of water has been
unidentifiable, Discovery
News explains. The Caltech team believes that they may have found the
smoking gun– evidence that this body of water actually existed, and to the
scale estimated. In a press release
from Caltech, Roman DiBiase, a postdoctoral scholar at Caltech and lead author
of the paper, explains that while this evidence does not prove the existence of
water on the planet, it is the strongest evidence to suggest it may have
existed.
Scientists
hypothesize that if the northern hemisphere had been covered in water, the
border between the lowlands and the highlands would have been the coastline for
the water. The team used the high-resolution images to study an area just to
the right of the supposed coastline, examining the photos for clues that might
reveal evidence of a large body of water. Satellite images have already shown
that the area was carved in inverted channels. An inverted channel occurs when
sediment is carried along a flowing river and deposited, and eventually worn
away, creating a ridge-like feature. The scientists specifically looked at the
images to see if they could determine the source of the water that had formed the
inverted channels. They found evidence of an abrupt increase in slope at one
point of the channels, suggesting that the water had dumped off into a larger
body of water instead of continuing its journey. For the first time, a
research team has discovered evidence of a larger body of water that was not
limited by geographical constraints such as crater walls.
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