Early Water

03/15/0703/15/07

MARS Early Water
March 2004
Did Life as We Know It Once Exist on Mars?

NASA's mission briefing (the week of 3 March 2004) on the progress of the Mars rover at Meridiani Planum, introduced startling new evidence of water once abundant on the red planet and the astrobiological puzzle of the close association of water and sulfur. The evidence of the Mars Exploration Rover (MER) called Opportunity clearly showed what some planetary scientists and exobiologists call "overwhelming evidence" of water–lots of water–existing on the planet Mars.

As a key to the existence of water, the findings announced at NASA headquarters indicate that the abundance of vast salt and sulfur traces and deposits are good indicators for massive water activity in the distant geological past. Specifically, Opportunity has shown that the heavy salt content on the outcropping rock is four times the amount found on the ground and with a quantity of sulfate. "You have to have a lot of water involved to get these results....Mars was habitable for a long period of time," said Steve Squyres, principal scientist for the rovers at NASA. [1]

The support for strong fluvial activity is evidenced in:

the Jarosite rock (composed of iron rich materials, iron sulfate hydrate, etc.); usually this indicates the rock's wet history having been in an acidic lake or an acidic hot springs environment.

evidence of sulfate in rocks; and,

massive amounts of salt in the samples, four times higher than that which is in the ground

El Capitan Rock

The "brewing evidence" shows a strong case for an evaporation sequence of conditions that moved from high levels of sulfur to sodium chloride (NaCl) (water-soluble solid) to bromide, as well as salt-rich brine material, all indicative of strong water activity where byproducts precipitated out of brine.

The recent Mars findings are unique and could be the historical "smoking gun" that will lead to further evidence of a once living habitat for life on Mars. Advanced analysis through the Moessbauer spectrometer and alpha X-ray spectrometer (provided by the international team from Mainz and the Max Planck Institute in Germany) indicates

that ground water could create an environment favorable for life. In short, the signs of strong water movement around and through the rocks allow the rocks to speak of environments within meteorite craters that could have had all the right triggering mechanisms for life that we find here on earth.

In the coming days (Sols), the Opportunity team will also look at the fantastic accumulation of different spherical anomalies NASA calls "blueberries". Even thoug Left sphere is cut by RAT for analysis
Courtesy: NASA/JPL h the material is simple "grey" rounded pebble-like structures, they hold possibly additional clues to water activity. These round particles (l mm thick) could be from volcanic hailstones, droplets of volcanic glass, or they could be spherical concretions that formed when there was liquid water in a rock.

Another sign of water comes from the holes within the rocks which are clearly evident. As crystals grow within rock, they become tabular like medicine pills. As they grow, they push the rock aside. When the mixture of water chemistry dissolves away, or erodes away, they leave tabular voids, or in some instances small spheres. Thus, the rocks have holes because:

the rock has not dissolved but the inner material has precipitated out of the rock; or
unique water chemistry and stratigraphy allowed the rock to soak up water like a sponge, and as the holes increase in size wherever precipitation grows, it replaces the rock. [2]

Thus, there are two basic scenarios of geological surface activity in the Martian past that one needs to consider:

either there was a tremendous amount of interaction from volcanic activity which resulted in an accumulation of basaltic ash that was later drenched with water; or
Martian sediments were formed and are in their present condition because of evaporating brine (water with a lot of salt).

Dr. Jim Garvin (NASA's leading scientist for Mars and Moon explorations), Ed Weiler (associate director of NASA), and other experts were very careful not to give reporters any time-line for the early existence of water on Mars, while other scientists are willing to say this would fall within a geological time period of 3 to 4 billion years ago. This writer recalls talking to Garvin in the mid-1980s when Garvin spoke of his interest in participating in a far-reaching program of "exploring Mars that would turn a dream into reality." [3]

In conclusion, NASA now agrees that there was an extensive presence of water on the Martian surface for an extended period of time. Whether this was long enough to trigger life as we define it on planet Earth remains to be seen. The variety of the evidence suggests that the next mission is to find "fossils" which will be the confirmation of the beginnings of the great chain of life.

Life might not have been so fortunate to continue as it did on planet earth, but there is no clear clue why it would not have started. We know that Earth, itself, has had many cataclysmic epochs where massive extinctions took place all over the globe. Could Mars have been so unlucky that a similar extinction ultimately destroyed all life? Let's hope we don't have to stay tuned too long until the next chapter of life unfolds on Mars.

References:
1. Dr. Steve Squyres, principal scientist for MER exploration at NASA briefing 3 March 2004.
2. Bentley Clark at press conference 3-03-04.
3. Personal conversation with Dr. Jim Garvin at time of SIR-A briefings, JPL, Spring 1986.

Site Last updated January 22,2006