|The magnificent Viking 2 lander panorama.|
This is one the first images
that I remember seeing on TV .
Curiosity finds Organics!
|Gale Crater as seen by the Curiosity Rover.|
An ancient "mud flats" long ago dried up
maybe leaving clues to past
Remembering Wolf Vishniac--April 22, 1922 – December 10, 1973.
|Professor Wolf Vishniac , who would|
have found Life on Mars . I was
introduced to him on Sagan's show
"Cosmos" 1979 . We would have
never heard of him with out Carl Sagan's
enthusiasm for Mars.
microorganisms, while the latter would measure the changes in the amount of light passing through the growth chamber, (4)>>Microorganisms, such as bacteria, turn a clear culture medium cloudy [turbid] as they grow, and the light sensor would detect such changes. The pH measurement would complement the turbidity measurement, providing an independent check on growth and metabolism.” If used by NASA, this would be the first instrument of its kind on any spacecraft. Its aim was to be placed on a future Mars lander. Since NASA's Curiosity rover landed on Mars in 2012, it has sifted samples of soil and ground-up rock for signs of organic molecules—the complex carbon chains that on Earth form the building blocks of life. Past detections have been so faint that they could be just contamination. Now, samples taken from two different drill sites on an ancient lakebed have yielded complex organic macromolecules that look strikingly similar to kerogen, the goopy fossilized building blocks of oil and gas on Earth. At a few dozen parts per million, the detected levels are 100 times higher than previous finds, but scientists still cannot say whether they have origins in biology or geology. The discovery positions scientists to begin searching for direct evidence of past life on Mars and bolsters the case for returning rock samples from the planet, an effort that begins with the Mars 2020 rover.
NOTES AND COMMENTS:
(1)>>Getting to Mars still isn’t easy.Let me give you an example. On Mars, the atmosphere is thinner than here. As a result, there is a large temperature difference between the surface and the air. What this practically means, is that if we were standing on Mars our feet and our head would experience different "weather". Amazing, isn't it? Would you imagine your feet having 10 degrees Celcius and your head -20! Now, this fact is back-projected on Earth. First of all, we learn something more for our planet, that the temperature homogeneity that we experience is not a tautology but is a distinct feature of our Earth. But, then a scientist may think "ok, we have a thicker atmosphere, but this doesn't mean that there is absolutely no temperature difference". So, they start measuring it and let's say that they find some small difference.(2)>>The NASA Viking landers took samples of soil on Mars and tested them for signs of organic carbon. Here's some detail about the Viking lander missions that deserves a mention. The two Viking landers each carried 4 different biological experiments to detect life. Amazingly, 3 of the 4 life detection experiments produced a positive result. The 4th experiment which tested for actual organic content of the Martian soil was negative and the scientific consensus was that this meant that organic life could not be present in the soil. However, the recent discovery of perchlorate in the soil on Mars has caused a reevaluation of the experiment which shows that there could have been up to several percent of organic matter in the soil but this would have been destroyed by the heating process of the experiment if perchlorate was also present in the Martian soil. In view of this controversy the official scientific consensus is still that the evidence for life on Mars from the Viking experiments is "inconclusive."No other successful missions to Mars since Viking have contained any experiments designed to directly search for life. Which is a pretty incredible omission really when you think about it. A conspiracy theorist might almost imagine that the mission controllers did not want to public ally settle the question once and for all of whether or not there is life on Mars. Perhaps there are other reasons for the lack of follow up missions to analyse Martian soil directly for life given the intriguing results of the Viking experiments. (3)>>organic molecules. Parts of Mars were capable of supporting life as we know it for lengthy stretches in the ancient past—perhaps hundreds of millions of years at a time, new observations by NASA's Mars rover Curiosity suggest. Since it landed inside the Red Planet's Gale Crater in August 2012, Curiosity has studied a number of different rocks over an elevational range of about 650 feet (200 meters), which represents a time span of tens of millions to hundreds of millions of years.The rovers' analyses indicate that the environment within Gale Crater changed considerably during this period, but never in a way that would preclude life from forming or surviving, mission scientists said during a news conference here at the annual fall meeting of the American Geophysical Union . (4)>>Microorganisms, such as bacteria. It is possible that Life from Earth has been transfered to Mars ? While all spacecraft sent to Mars have to be sterile , It MAY NOT BE the Case . [ see : http://cosmology.com/LifeOnMars.html ] Earth microbes can survive on Mars on certain conditions . Fungi are extremophiles that can survive harsh conditions and environments like deserts, caves or nuclear accident sites., scientists recently reported in the journal Astrobiology. A few of them even managed to cap their year in Mars-like space by reproducing.Although Mars-based life may not use DNA genetic material, then again, it just might. It certainly seems to have worked well for us here on Earth.Even though few of the fungi exposed to Mars-like conditions survived well enough to reproduce, in all cases, at least a fraction did.