[X] My Assistant

[Guest_RGClark_*]

Lichen Survives In Space.
"Leopoldo Sancho from the Complutense University of Madrid, indicate that lichens have the capacity to resist full exposure to the harsh space conditions, especially high levels of UV radiation. Analysis post flight showed a full rate of survival and an unchanged ability for photosynthesis."
http://www.physorg.com/news8054.html

The algae in lichen rely on photosynthesis as plants do, therefore metabolize CO2. Therefore they might be able to survive as well on Mars. However, some photosynthetic organisms require oxygen as well. It's unclear if the species tested could survive in a largely CO2 atmosphere, though Mars does contain small amounts of oxygen in its atmosphere.

Gil Levin argued that some patches on rocks at the Viking landing sites gave the appearance of lichen:

Color and Feature Changes at
Mars Viking Lander Site.
J. Theor. Biol. (1978) 75, 381-390
http://mars.spherix.com/color/color.htm


Bob Clark

[edstrick]

We've recently had a fairly extensive discussion of Levin's paper and other information on another thread here. In summary, though he was one of the very first people to try to work with Viking Lander color data, his analysis was half-competetent by somebody who barely understood what he was doing and it's results have been used in support of inferences that they do not substantially support. The paper also was "shopped around" to several peer-reviewed journals and finally published in a minor journal who's reviewers probably didn't have a clue what they were reviewing.

[Guest_RGClark_*]

We've recently had a fairly extensive discussion of Levin's paper and other information on another thread here.  In summary, though he was one of the very first people to try to work with Viking Lander color data, his analysis was half-competetent by somebody who barely understood what he was doing and it's results have been used in support of inferences that they do not substantially support.  The paper also was "shopped around" to several peer-reviewed journals and finally published in a minor journal who's reviewers probably didn't have a clue what they were reviewing.

Simulations Show Liquid Water Could Exist on Mars.
"University of Arkansas researchers have become the first scientists to show that liquid water could exist for considerable times on the surface of Mars."
...
"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."
...
"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."
http://www.physorg.com/printnews.php?newsid=7981



It may prove fruitful to make a comparison between the spectra of the moist Mars simulant in this experiment and the "mud-like" material seen with the "Magic carpet" at the Gusev landing site.



- Bob