Lichen survive in space. Perhaps also on Mars?

[exoscientist]

Lichen Survives In Space.<br />"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. "<br />http://www.physorg.com/news8054.html<br /><br /> 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.<br /><br /> Gil Levin argued that some patches on rocks at the Viking landing sites gave the appearance of lichen:<br /><br />Color and Feature Changes at <br />Mars Viking Lander Site.<br />J. Theor. Biol. (1978) 75, 381-390<br />http://mars.spherix.com/color/color.htm<br /><br /><br /><br /> Bob Clark <div class="Discussion_UserSignature"> </div>

 

[igorsboss]

Surviving is different than thriving. A seed can survive harsh conditions, until it sprouts. Then it needs a whole bunch of support to thrive.

 

[exoscientist]

<i>This is just one more of those 'life is rife' claims. Mars is simply too cold for life, with temps of about Minus 58 C. And the surface is frozen down 1-2 km. in most places. Lichens cannot live at such temps, nor without an atmosphere. Nor can such cells have evolved in such a hostile environment. <br />It's exceptionally likely that Mars is simply lifeless, as are all other areas in the solar system, except the earth. <br />"Show us one cell, a single cell. That's all we ask." <br />Can it be that hard, if "life is rife"</i><br /><br /><br /> Space is colder, yet they survived.<br /> Send a microscope to Mars and I'll show you a cell. All that was sent with the MER rovers was a magnifying glass.<br /> How many bacteria can you see with a magnifying glass?<br /><br /><br /> - Bob <div class="Discussion_UserSignature"> </div>

 

[centsworth_II]

<font color="yellow">"Send a microscope to Mars and I'll show you a cell."</font><br /><br />Well, you'll get your chance when Phoenix lands in a few years.<br /><br />"The atomic force microscope will provide sample images down to 10 nanometers--the smallest scale ever examined on Mars" -- from the Phoenix website<br /> <br />And from Astrobiology Magazine:<br />"The tiniest bacteria measure about 200 nanometers in size, and many believe that life can't get much smaller than that."<br /><br />So bacteria, if seen, should show up nicely. Trouble is, Phoenix will only dig down two or three feet. Deep enough to find ice, but bacteria???<br /><br />One thing is for sure. The same group or armchair scientists that combed the MER images for fossils laying on the ground will be out in force looking for micro fossils in the Phoenix images. <br /> <div class="Discussion_UserSignature"> </div>

 

[chew_on_this]

Same old same old.

 

[exoscientist]

<i>This is consistent with a cold surface of MINUS 58 C. more or less planetwide.</i><br /><br /> No, temperatures near the equator routinely exceed the melting point during the daytime.<br /> For a belt 20 degrees latitude above and below the equator, daytime, Summer temperatures can reach 80 F.<br /> This is a very large surface area for a planet 4000 miles wide.<br /> This is an important consideration when considering the possibilities of liquid water persisting on the planet.<br /> One such location on Mars is the fog-encased Noctis Labyrinthus canyon system, which is kilometers deep allowing pressure above the triple point year round:<br /><br />Noctis clouds. <br />http://photojournal.jpl.nasa.gov/jpegMod/PIA03213_modest.jpg<br /><br /><br /> - Bob Clark <div class="Discussion_UserSignature"> </div>

 

[centsworth_II]

<font color="yellow">"Permafrost exists in Siberia at much warmer temps down a few hundred meters. AS Mars is colder, the permafrost there is thousands of meters deep. And far, far colder."</font><br /><br />On Earth, bacterial life is being found virtually as deep as it is looked for, up to a mile or two now. In fact there is possibly more of Earth's biomass deep underground than on or near the surface. The limiting factor to life on Earth is NOT depth, but temerature. There is a limit to how deep in the rocky crust of Earth life may be found because at a certain depth, the temperature rises above what life can tolerate.<br /><br />It is reasonable to assume that temperatures in the martian crust also rises with depth. The core may be solid but it is certainly not cold! NO MATTER WHAT DEPTH a constant temperature amenable to life occurs at, it is there. If at any point in Mars' history life evolved and permeated Mars the way life permeates Earth, the life at that depth may still be there, having noticed not at all events over the past billions of years on the surface. <div class="Discussion_UserSignature"> </div>

 

[Philotas]

You`re speaking of more than you know, steve.<br /><br />Life on Venus(cloud tops) is being reconsidered, and Mars is more alive than ever. The retreat is non-existant; in fact, it`s a steady march forward.<br /><br /><br /><font color="yellow">The frozen ice has very likely been seen by MARSIS at those depths. This is consistent with a cold surface of MINUS 58 C. more or less planetwide.</font><br /><br />The MARSIS team say that the possibility of subsurface liquids are fare from ruled out. <div class="Discussion_UserSignature"> </div>

 

[chew_on_this]

/*ad hominem deleted*/ You'd have better luck convincing him the moon is made of green cheese.

 

[bonzelite]

from Discover Year in Science, vol 27 no.1, Jan 2006:<br /><br />"Life Turns up in the Most Unlikely Places:<br /><br />...Loneliest:<br /><br />Until the Larsen B ice shelf, which once capped part of Antarctica's coastal waters, broke up in 2002, researchers believed that nothing lived below it. Bacteria have proved them wrong. In July, Hamilton College geologist Eugene Domack and his collegues announced they had discovered a lumpy white bacterial mat growing on one patch of the pitch-dark sea floor and observed foot-long clams nearby. "This system is much more isolated than anything we've ever found before," Domack says. "It's way of making a living may be very different from anything we know about." <br /><br />