Mars, life

Flynn, C. et al., Spaceflight Cognitive Assessment Tool for Lunar-Mars Life Support Test Project Phase III Test, in Isolation NASA Experiments in Closed-Environment Living, Vol. 104, Lane, S.W., Sauer, R., and Feeback, D.L., Eds., Unicelt, Inc., San Diego, 2002, 155. 

A Ca-rich clinoptilolite tuff from Sweetwater County, Wyoming has successfully been used in columns to remove ammonium from the wastewater of the National Space Administration (NASA) regenerative life-support system test bed [120]. This forms part of the Lunar-Mars Life Support Test Project, and may be used on the International Space Station. 

Without carbon, the basis for life would be impossible. While it has been thought that silicon might take the place of carbon in forming a host of similar compounds, it is now not possible to form stable compounds with very long chains of silicon atoms. The atmosphere of Mars contains 96.2% CO2. Some of the most important compounds of carbon are carbon dioxide (CO2), carbon monoxide (CO), carbon disulfide (CS2), chloroform (CHCb), carbon tetrachloride (CCk), methane (CHr), ethylene (C2H4), acetylene (C2H2), benzene (CeHe), acetic acid (CHsCOOH), and their derivatives. 

The acceptance of the name was premature because both Russian and American efforts now completely rule out the possibility of any isotope of Element 102 having a half-life of 10 min in the vicinity of 8.5 MeV. Early work in 1957 on the search for this element, in Russia at the Kurchatov Institute, was marred by the assignment of 8.9 +/- 0.4 MeV alpha radiation with a half-life of 2 to 40 sec, which was too indefinite to support discovery claims. 

When considering how the evolution of life could have come about, the seeding of terrestrial life by extraterrestrial bacterial spores traveling through space (panspermia) deserves mention. Much is said about the possibility of some form of life on other planets, including Mars or more distant celestial bodies. Is it possible for some remnants of bacterial life, enclosed in a protective coat of rock dust, to have traveled enormous distances, staying dormant at the extremely low temperature of space and even surviving deadly radiation The spore may be neither alive nor completely dead, and even after billions of years it could have an infinitesimal chance to reach a planet where liquid water could restart its life. Is this science fiction or a real possibility We don t know. Around the turn of the twentieth century Svante Arrhenius (Nobel Prize in chemistry 1903) developed this theory in more detail. There was much recent excitement about claimed fossil bacterial remains in a Martian meteorite recovered from Antarctica (not since... 

The coupled methods, GC/MS and LC/MS, form very powerful combinations for simultaneous separation and identification of components of mixtures. Hence, these techniques have been used in such widely disparate enterprises as looking for evidence of life forms on Mars and for testing racehorses or athletes for the presence of banned drugs. 

Heaviside s last years were spent as an embittered recluse at Torquay, Devon where he allowed only a few people to visit him. For much of his life he suffered from recurring jaundice that was to prove fatal. He died on February 3, 1925. Heaviside s work has been an inspiration to countless electrical engineers and mathematicians. Time has enhanced the esteem in which he is held succeeding generations have spent many hours studying his writings. As a lasting honor, craters on Mars and the Earth s moon were named after him. 

Rosato, D. V., Plastic Replaces Aorta Permits Living Normal-Long Life, Newton-Wellesly Hospital-Massachusetts, Mar. 1987. 

For the above polyol blend viscosity (Brookfield, ASTM D-2196) = 1500 mPa-S at 23° C. For the reaction mixture working (pot) life 20 min Gardner circular dry times [72°F, 54% relative humidity (RH)] surface dry = 1.0 h, hard dry = 2.0 h, mar free = 3.5 h. For the finished coating gloss (ASTM D-523) = 90+ at 60° impact (ASTM D-2794) = 60 in.-lb direct, 10 in.-lb reverse Tabor abrasion (ASTMD-4060,1000 g load, 1000cycles, CS-17 wheel) = 95.6 mg pendulum hardness = 180 s MEK double rubs (ASTM D4752-95, 50 double rubs) = softened. 

The GC-MS instrument can be very compact and used in mobile equipment. A GC-MS device was used on the Viking Lander on the first Mars mission to search for organic compounds that would have provided evidence of life (none was detected). 

FIGURE 25.4 Typical strain-life plot for natural rubber at multiple 77-ratios. (From Mars, W.V. and Fatemi, A.,... 

Mars, W.V. et al.. Fatigue life analysis of an exhaust mount, in Constitutive Models for Rubber IV, Austrell, K., Ed., Swets Zeiflinger, The Netherlands, 2005, 23. 

Mars, W.V., Heuristic approach for approximating energy release rates of small cracks under finite strain, multiaxial loading, in Elastomers and Components—Service Life Prediction Progress and Challenges, Coveney, V., Ed., OCT Science, Philadelphia, 2006, 89. 

A drop of water contains an unimaginable number of molecules, as our molecular inset shows. Water is essential to life as we know it. The simple yet unusual fact that solid water (ice) floats atop liquid water allows life to exist on our planet. Just as important is the fact that water dissolves an immense range of chemical compounds Water is the solvent of life. In fact, water is so important to our perspective of life that the search for water is a key feature of our quest to discover life in other quarters of the galaxy. The inset photo of the surface of Mars, for example, shows no sign of water at present, but some erosional features appear to have been caused by flowing water in the past. 

Speculation about life on other planets probably began when humans discovered that the Earth Is not unique. We know that several other planets of the solar system bear at least some resemblance to our own. Why, then, should there not be life on Mars, or Venus, or perhaps on undiscovered Earthlike planets orbiting some other star ... 

How can scientists collect experimental evidence about possible life on another planet Sending astronauts to see for themselves is impractical at our current level of technology. Nevertheless, it is possible to search for life on other worlds without sending humans into space. In the late 1970s, NASA s Viking spacecraft lander collected a sample of dirt from Mars, the planet in our solar system most like Earth. The sample showed no signs of life. Nevertheless, speculation continues about Martian life. 

The photo below, taken by the Ttl/ng spacecraft, shows that the surface of Mars has been eroded, apparently by liquid water. More recent photos transmitted by Spirit and Opportunity convince scientists that this was the case. Apparently, Mars was once much warmer than it is today. Planetary scientists speculate that at one time the atmosphere of Mars may have contained large amounts of carbon dioxide, setting up a greenhouse effect that made the surface of that planet warmer and wetter. Might there, then, have been life on Mars at some earlier time Molecular stmctures found in meteorites thought to come from Mars have been interpreted to show that there was once life there, but these results are controversial. 

Tung HC, NE Bramall, PB Price (2005) Microbial origin of excess methane in glacial ice and implications for life on Mars. Proc Natl Acad Sci USA 102 18292-18296. 

C Sending spacecraft to Mars to search for other life forms... 

Not only would proof of the existence of life on Mars be a great sensation, but even the discovery of precursors of life, such as biomolecules or building blocks for their formation, would change our perspective greatly (see also Chap. 11). 

As far as life on other planets is concerned, Mars occupies a special place ... 

The climate on Mars is not so inimical to life as that on Earth s other direct neighbour, Venus. 

The phase of science fiction stories about little green men from Mars is hopefully over, and the question can only be are there, or were there ever, real living systems there, or can we find traces of precursors of life in the form of biomolecules ... 

Free water, the essential precondition for life as we know it, has recently been detected on Mars images taken by the high resolution stereo camera (HRSC) on board ESA s Mars Express spacecraft show a patch of water ice on the floor of an unnamed crater near the Martian north pole. Geomorphic studies indicate that the surface of Mars can be divided into two types (Jaumann et al 2002) ... 

In spite of many new, and in some cases sensational, results concerning the Red Planet, we are still no nearer to answering the question of life on Mars. Four alternatives appear possible for Mars ... 

Could it be the case that microorganisms, like the suspected fossils in the Mars meteorite ALH 84001, exist in the Martian soil This question leads to the counterquestion as to whether it has previously been possible to detect and study life (primitive life forms) under highly extreme conditions. Are there such conditions on Earth We now know quite a lot about extremophiles such as the thermophilic, halophilic and hyperthermophilic microorganisms. 

This makes it clear that a vast amount of work must still be done on Mars in order to obtain a final answer as to whether life exists, or ever existed, on the Red Planet. 

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