Extraterrestrial search

The analysis of extraterrestrial matter is concentrated on the detection of nucleic acid and protein building blocks, i.e., N-heterocycles and amino acids. The search for such compounds began immediately after the fall of the Murchison meteorite. Twenty-two amino acids were detected in it as early as 1974 eight of them pro-teinogenic, ten which hardly ever occurred in biological material, and four which were unknown in the biosphere. Up to now, about 70 amino acids have been identified (Cronin, 1998), the most common being glycine and a-aminoisobutyric acid. The latter is a branched-chain amino acid with the smallest possible number of carbon atoms. The most frequently found amino acids occur in concentrations of... 

So where are they then This question, now famous, is attributed to Enrico Fermi he was reacting to an observation, made by a member of the audience at a physics conference in Los Alamos in 1950, that there must be extraterrestrial intelligence (ETI). (The search for ETI is known as SETI, search for extraterrestrial intelligence.) The question is now known as the Fermi paradox initial investigations with the goal of solving it took place a few years after Fermi s question was posed. 

The search for extraterrestrial intelligence was originally coordinated by the SETI Institute in Mountain View, California, founded in 1984 however, in 1992,... 

MacDermott, A. J. The weak force and SETH The search for extraterrestrial homochirality in Physicd Origin of Homochirdity... 

We have taken samples of the surface of the Moon, by man, and the surface of Mars, by robot, and searched these samples for signs of life nothing found. Contrast this scenario with one in which some extraterrestrial civilization sampled the surface of the Earth for signs of life. It is difficult to imagine that they could find samples that did not contain signs of life indeed did not contain an abundance of living organisms. The Earth teems with life. 

Horowitz, P. and Sagan, C. (1993). Five years of Project META an all-sky narrow-band radio search for extraterrestrial signals. Astrophys. J., 415, 218-33. 

In the movie Contact, Dr. Elbe Arroway is scolded and told that her proposal to search for extraterrestrial life seems less like science and more like science fiction. She responds, Science fiction. You re right, it s crazy. In fact, it s even worse than that, it s nuts. You wanna hear something really nutty I heard of a couple guys who wanna build something called an airplane, you know you get people to go in, and fly around like birds. It s ridiculous, right ... Look, all I m asking is for you to just have the tiniest bit of vision. 

Radio-astronomy searches (Project Ozma) for communications from intelligent extraterrestrial beings have been carried out at this frequency see Interstellar Communication, A. G. W. Cameron, etL, Benjamin, New York, 1963 Communication With Extraterrestrial Inteltt-genee, C. Sagan, ed. MIT Press, 1973. 

In the search for extraterrestrial signatures of life, we need to distinguish among Solar System sites, extrasolar system sites, and the search for intelligent life. It is likely that within the 21st century most potential life-bearing... 

Dyson, J. F. (1966) The Search for Extraterrestrial Technology in Perspectives in Modem Physics, ed. R. E. Marshak, John Wiley and Sons, New York, pp. 643-644. 

Ibid. See also A.T. Lawton, Infrared interstellar communication, Spaceflight, 13(3) 83-85 (1971) C. H. Townes, At what wavelengths should we search for signals from extraterrestrial intelligence Proceedings of the National Academy of Science U.S.A. 80 1147-1151 (1983) J. D. Rather, Lasers Revisited their superior utility for interstellar beacons, communications, and travel, Journal of the British Interplanetary Society, 44 385-392 (1991). 

Guillermo A. Lemarchand, Detectability of extraterrestrial technological activities, http / /www.coseti.org/lemarch 1. htm. See also, Freeman Dyson, Search for artificial stellar sources of infrared radiation, Science 131 1667-1668 (1959) Freeman Dyson, The search for extraterrestrial technology, in Perspectives in Modern Physics (Essays in Honor of Hans Bethe), ed. R. E. Marshak (New York John Wiley Sons, 1966). 

Earth may be just one of many models of planets that can evolve complex life. We do not know whether it is even practical or logical to assume that planets that exist outside our perception of a habitable zone could harbor life, particularly life that we know nothing about. Our practical search for extraterrestrial life is focused on water-rich planets and moons because of the possibility that they can support Earth-like life. That does not preclude... 

The FITC labeling method was also applied to chiral separations of amino acids on a microchip to determine the enantiomeric ratios of amino acids found on a meteorite [27], Since biotic amino acids are normally single enantiomers, chiral separations of amino acids are not truly clinical in nature, but illustrate the potential for chiral separations of small molecules of clinical interest. Ma-thies and co-workers used this technique to search for evidence of life in extraterrestrial environments. Enantiomeric forms of Val, Ala, Glu, and Asp could be discriminated by addition of a-, (3-, or y-cyclodextrin (CD) to the run buffer. Improved resolution with faster separations was found with respect to conventional CE. This method has been modified, by addition of SDS to the buffer, to perform cyclodextrin-modified micellar electrokinetic chromatography (CD-MEKC) [28]. Increasing the SDS concentration decreased the magnitude of elec-troosmotic flow (EOF), increasing the effective migration distance, and therefore the resolution on the microchips. 

Westall, F., 1999, The nature of fossil bacteria. A guide to the search for extraterrestrial life, J Geophys Res, 104 (E7) 16437-16451. 

Detection of biomass is an important application of analytical pyrolysis and it includes several topics. One such topic is the measurement of microbial biomass in attempts to substitute for traditional microbiological methods. Another topic is the detection of specific biomarkers for geochemical logging purposes. Pyrolytic studies were also useful in organic marine geochemistry [72]. An interesting application of biomass detection is the search for life in extraterrestrial samples. 

AMANDA has yet to observe an extraterrestrial neutrino source, but she has demonstrated the cost-effectiveness and robustness of the technique. The detector is very versatile it addresses many different neutrino physics subjects and sets the most stringent upper limits on Galactic and extragalactic neutrino fluxes. The improved search for diffuse fluxes, which has ruled out several predictions, along with the extended four-year search for point sources has started to constrain the enormous parameter space that exist in many models of neutrino production. The reported experimental limits on the diffuse neutrino flux are less than an order of magnitude above the Waxman-Bahcall bound ( Waxman and Bahcall, 1999). As more of the data on tape is analyzed, AMANDA sensitivities will continue to improve. This is a very exciting time in neutrino astronomy and we look forward to neutrino astrophysics with next generation of neutrino telescopes. 

Tarter, J.. The Search for Extraterrestrial Intelligence (SETI). Annu. rev. Astron. Astrophys. 2001 39 511-48. 

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