Friday, August 2, 2013
Oceans on Mars?
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.