Permanent Human Settlement of the Earth, Space and Ocean Frontiers

Saturday, March 04, 2006

Wet Mars?

Ralph Buttigieg

Sydney, New South Wales


Water is the most essential of resources, without water there will be no Martian colonies. However maybe theres ample water on Mars and some of it even in liquid form, not just ice. Consider the following.

In 2003 ESA sent the Mars Express probe to Mars and although its Beagle lander was a failure, the orbiter has provided important information. Like finding water ice at the poles, inside craters, (See the picture above)and in a frozen sea at the equator.

NASA's Mars Odyssey also detected large amounts of water. From the Odyssey report:

The new maps combine images from the Mars Orbiter Laser Altimeter (MOLA) on the Mars Global Surveyor with Mars Odyssey spectrometer data through more than half a Martian year of 687 Earth days. From about 55 degrees latitude to the poles, Mars boasts extensive deposits of soils that are rich in water-ice, bearing an average of 50 percent water by mass. In other words, Feldman said, a typical pound of soil scooped up in those polar regions would yield an average of half a pound of water if it were heated in an oven.

The tell-tale traces of hydrogen, and therefore the presence of hydrated minerals, also are found in lower concentrations closer to Mars' equator, ranging from two to 10 percent water by mass. Surprisingly, two large areas, one within Arabia Terra, the 1,900-mile-wide Martian desert, and another on the opposite side of the planet, show indications of relatively large concentrations of sub-surface hydrogen.

Its commonly believed that the low Martian atmospheric pressure and low temperatures would not allow liquid water to exist. It would either quickly boil away or freeze solid. Well last year researchers put this to the test. They poured a brine solution on some Mars soil stimulant and put it into a Mars simulation chamber. The water didn't evaporate away, it soaked into the soil and formed mud. The atmospheric humidity is nearly 100% so its difficult for water to evaporate. According to the scientists:

"There's a huge decrease in the evaporation rate the colder it gets, more than anyone realized," Chittenden said. With the dissolved sodium and calcium in the water, the freezing point for the brine mixtures drops to 21 degrees below zero Celsius for salt water and 50 degrees below zero for water containing calcium chloride. Temperatures on Mars vary between 125 degrees below zero Celsius and 28 degrees above at different latitudes and different times of the day. Thus, there is a possibility that liquid water could exist on the planet's surface at different locations and times of day. "Brine formation could considerably increase the stability of water on Mars by both extending the temperature range over which liquid water is stable to negative-40 degrees Celsius and by decreasing the evaporation rates by two orders of magnitude," the researchers wrote.

The Mars Rover are also providing evidence for a wet Mars. Have a good look at the picture below This link shows other Rover images supporting a wet Mars.

Mars rover tracks within Gusev Crater show what may be water squeezed out of the soil by the weight of the wheeled Spirit robot. The water subsequently freezes into a whitish residue left in wheel marks.Credit NASA/JPL/Cornell (Could the white residue be salt? Ralph)

Dennis has already discussed what water on Mars means to Martian exploration, in my next post we'll take a look at this topic again but from a different angle. In the mean time I'll leave you with this thought, the Rovers have been on Mars for two years and have been unable to settle this question. An astronaut could have kicked the dirt and and discovered any water in minutes.

Update: The Dawn mission to Ceres and Vesta has been officially cancelled This is disappointing as recent Hubble information provide evidence of plentiful water on Ceres.

Snapshots of the asteroid 1 Ceres taken by the Hubble Space Telescope provide clues about the asteroid's interior make-up. The bright spot that appears in each image is a mystery. (Could the bright spot be ice?Ralph) Credit: NASA, ESA, J. Parker (Southwest Research Institute), P. Thomas (Cornell University), and L. McFadden (University of Maryland, College Park)

Antarctica: Laurie Geohegan from the JRM Antarctic Kayak team has injured his elbow in a small fall and has been left on the Argentine Islands for pickup by the yacht Spirit of Sydney. The remaining two kayakers are still paddling south.