Search NASA⌕ Search

SEARCH · Search NASA

Results for “Life detection”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 199 records · Page 11

Enzyme-Cascade Analysis of the Rio Tinto Subsurface Environment: A Biosensor Experiment

The Portable Test System (PTS), designed & developed by Charles Rivers Laboratories, Inc. (Charleston, SC) is a portable instrument that was designed to perform analysis of enzymatic assays related to rapid assessment of microbial contamination (Wainwright, 2003). The enzymatic cascade of Limulus Amebocyte Lysate (LAL) is known to be one of the most sensitive techniques available for microbial detection, enabling the PTS to be evaluated as a potential life detection instrument for in situ Astrobiology missions. In the summer of 2003 the system was tested as a part of the Mars Astrobiology Research and Technology Experiment (MARTE) ground truth science campaign in the Rio Tinto Analogue environment near Nerva, Spain. The preliminary results show that the PTS analysis correlates well with the contamination control tests and the more traditional lab-based biological assays performed during the MARTE field mission. Further work will be conducted on this research during a second field campaign in 2004 and a technology demonstration of a prototype instrument that includes autonomous sample preparation will occur in 2005.

McKay, David S.↗

The planets and life.

It is pointed out that planetary exploration is not simply a program designed to detect life on another planet. A planet similar to earth, such as Mars, when studied for evidence as to why life did not arise, may turn out to be scientifically more important than a planet which has already produced a living system. Of particular interest after Mars are Venus and Jupiter. Jupiter has a primitive atmosphere which may well be synthesizing organic molecules today. Speculations have been made concerning the possibility of a bio-zone in the upper atmosphere of Venus.

Young, R. S.↗

Enzymatic Activity Detection via Electrochemistry for Enceladus

Electrochemical detection of biological molecules is a pertinent topic and application in many fields such as medicine, environmental spills, and life detection in space. Proteases, a class of molecules of interest in the search for life, catalyze the hydrolysis of peptides. Trypsin, a specific protease, was chosen to investigate an optimized enzyme detection system using electrochemistry. This study aims at providing the ideal functionalization of an electrode that can reliably detect a signal indicative of an enzymatic reaction from an Enceladus sample.

astrobiolog↗

Publications of the planetary biology program for 1975: A special bibliography

The Planetary Biology Program of the National Aeronautics and Space Administration is the first and only integrated program to methodically investigate the planetary events which may have been responsible for, or related to, the origin, evolution, and distribution of life in the universe. Research supported by this program is divided into the seven areas listed below: (1) chemical evolution, (2) organic geochemistry, (3) life detection, (4) biological adaptation, (5) bioinstrumentation, (6) planetary environments, and (7) origin of life. The arrangement of references in this bibliography follows the division of research described above. Articles are listed alphabetically by author under the research area with which they are most closely related. Only those publications which resulted from research supported by the Planetary Biology Program and which bear a 1975 publication date have been included. Abstracts and theses are not included because of the preliminary and abbreviated nature of the former and the frequent difficulty of obtaining the latter.

Souza, K. A.↗

Mission perspectives

Handling the Martian samples by requiring that they be subjected to a complex protocol designed to detect life, which, if present, will then be assessed for its effects on terrestrial life forms is addressed. Sample testing must be performed within facilities that ensure that such Martian organisms cannot be accidentally introduced to Earth's biosphere during the assessment process. An Orbiting Quarantine Facility (OQF) designed to permit the detection and characterization of Martian life forms, while affording the Earth and its inhabitants the maximum level of protection, is analyzed and described.

Source record↗

No Organic Compounds on Mars? Understanding the Structure of Spiral Galaxies

A prime goal of the Viking missions to Mars is to search for life on that planet. Each of the two landers incorporate three specific life-detection experiments, and all have operated successfully. However, as any newspaper reader knows, the results are ambiguous, in that some experiments suggest a highly active martian biology while others appear to indicate that the samples are sterile. It would be premature to conclude from the results of the biological experiments that martian life forms have definitely been detected. In addition, the picture is clouded by unexpected results from another Viking experiment, which is designed to detect organic and inorganic chemical compounds in the martian soil. In Science for 1 October 1976, K. Biemann of MIT and ten of his colleagues report the first results from the Viking 1 Gas-Chromatograph/Mass Spectrometer (GCMS) experiment.

Morrison, Nancy D.↗

Super-long Anabiosis of Ancient Microorganisms in Ice and Terrestrial Models for Development of Methods to Search for Life on Mars, Europa and other Planetary Bodies

Successful missions to Mars, Europe and other bodies of the Solar system have created a prerequisite to search for extraterrestrial life. The first attempts of microbial life detection on the Martian surface by the Viking landed missions gave no biological results. Microbiological investigations of the Martian subsurface ground ice layers seem to be more promising. It is well substantiated to consider the Antarctic ice sheet and the Antarctic and Arctic permafrost as terrestrial analogues of Martian habitats. The results of our long-standing microbiological studies of the Antarctic ice would provide the basis for detection of viable microbial cells on Mars. Our microbiological investigations of the deepest and thus most ancient strata of the Antarctic ice sheet for the first time gave evidence for the natural phenomenon of long-term anabiosis (preservation of viability and vitality for millennia years). A combination of classical microbiological methods, epifluorescence microscopy, SEM, TEM, molecular diagnostics, radioisotope labeling and other techniques made it possible for us to obtain convincing proof of the presence of pro- and eukaryotes in the Antarctic ice sheet. In this communication, we will review and discuss some critical issues related to the detection of viable microorganisms in cold terrestrial environments with regard to future searches for microbial life and/or its biological signatures on extraterrestrial objects.

Abyzov, S. S.↗

The Grayness of the Origin of Life

In the search for life beyond Earth, distinguishing the living from the non-living is paramount. However, this distinction is often elusive, as the origin of life is likely a stepwise evolutionary process, not a singular event. Regardless of the favored origin of life model, an inherent “grayness” blurs the theorized threshold defining life. Here, we explore the ambiguities between the biotic and the abiotic at the origin of life. The role of grayness extends into later transitions as well. By recognizing the limitations posed by grayness, life detection researchers will be better able to develop methods sensitive to prebiotic chemical systems and life with alternative biochemistries.

Origin of life↗

LOW-COST MARS IN-SITU ASTROBIOLOGY MEASUREMENTS AND STRATEGY.

Identifying evidence of Martian life would revolutionize our understanding of biological processes and predictions about the likelihood of life elsewhere. Of all Solar System bodies, Mars remains a primary life-detection target because conditions during its first 500 million years resembled those on Earth when early life emerged [1]. The search for life on Mars should include identifying preserved remains of ancient life from this more habitable epoch in Martian history relative to today, as well as searching for evidence of potential modern survivors that could have found refuge in locations with available liquid water and protection from the harsh surface environment [2]

M B Wilhelm↗

What Would Constitute Evidence for Life on Icy Moons?

For the first time since Viking, NASA is considering missions that would include life detection as a primary objective, making it critical to develop and evaluate a diverse set of strategies for seeking evidence of life. The central question is: what should be the target of our search that, if found, would constitute a near-certain evidence for life? Since life on icy moons might be quite different from terrestrial life, we should concentrate on features of biological systems that are considered universal and are unlikely to emerge through abiotic means.

Icy Moons↗

Analysis and interpretation of Viking labeled release experimental results

The Viking Labeled Release (LR) life detection experiment on the surface of Mars produced data consistent with a biological interpretation. In considering the plausibility of this interpretation, terrestrial life forms were identified which could serve as models for Martian microbial life. Prominent among these models are lichens which are known to survive for years in a state of cryptobiosis, to grow in hostile polar environments, to exist on atmospheric nitrogen as sole nitrogen source, and to survive without liquid water by absorbing water directly from the atmosphere. Another model is derived from the endolithic bacteria found in the dry Antarctic valleys; preliminary experiments conducted with samples of these bacteria indicate that they produce positive LR responses approximating the Mars results. However, because of the hositility of the Martian environment to life, and the failure to find organics on the surface of Mars, a number of nonbiological explanations were advanced to account for the Viking LR data. A reaction of the LR nutrient with putative surface hydrogen peroxide is the leading candidate. Other possibilities raised include reactions caused by or with ultraviolet irradiation, gamma-Fe2O3, metalloperoxides or superoxides.

Levin, G. V.↗

Mars Sample Handling Protocol Workshop Series: Workshop 2

Numerous NASA reports and studies have identified Planetary Protection (PP) as an important part of any Mars sample return mission. The mission architecture, hardware, on-board experiments, and related activities must be designed in ways that prevent both forward- and back-contamination and also ensure maximal return of scientific information. A key element of any PP effort for sample return missions is the development of guidelines for containment and analysis of returned sample(s). As part of that effort, NASA and the Space Studies Board (SSB) of the National Research Council (NRC) have each assembled experts from a wide range of scientific fields to identify and discuss issues pertinent to sample return. In 1997, the SSB released its report on recommendations for handling and testing of returned Mars samples. In particular, the NRC recommended that: a) samples returned from Mars by spacecraft should be contained and treated as potentially hazardous until proven otherwise, and b) rigorous physical, chemical, and biological analyses [should] confirm that there is no indication of the presence of any exogenous biological entity. Also in 1997, a Mars Sample Quarantine Protocol workshop was convened at NASA Ames Research Center to deal with three specific aspects of the initial handling of a returned Mars sample: 1) biocontainment, to prevent 'uncontrolled release' of sample material into the terrestrial environment; 2) life detection, to examine the sample for evidence of organisms; and 3) biohazard testing, to determine if the sample poses any threat to terrestrial life forms and the Earth's biosphere. In 1999, a study by NASA's Mars Sample Handling and Requirements Panel (MSHARP) addressed three other specific areas in anticipation of returning samples from Mars: 1) sample collection and transport back to Earth; 2) certification of the samples as non-hazardous; and 3) sample receiving, curation, and distribution. To further refine the requirements for sample hazard testing and the criteria for subsequent release of sample materials from quarantine, the NASA Planetary Protection Officer convened an additional series of workshops beginning in March 2000. The overall objective of these workshops was to develop comprehensive protocols to assess whether the returned materials contain any biological hazards, and to safeguard the purity of the samples from possible terrestrial contamination. This document is the report of the second Workshop in the Series. The information herein will ultimately be integrated into a final document reporting the proceedings of the entire Workshop Series along with additional information and recommendations.

Rummel, John D.↗

To Boldly Go: America's Next Era in Space. Living Places in Other Solar Systems

Dr. Sargent noted that evidence of other solar systems that might sustain life, particularly human life, is being sought. Protoplanetary (or debris) disks have been observed and are considered evidence that other solar systems exist or are being formed. Also observed is a wobble which is seen as evidence of circulation around a celestial body and gaps that are created by the potential planet. One indicator of life may be these rings or disks of debris around stars. Interferometers, which are telescopic devices that consist of multiple lenses, are being developed in order to better see celestial objects and what may be found around them. Other methods for improving celestial viewing capabilities are also under development. She spoke of particularly looking for wobble and gaps and debris disks where new planets are being formed in an effort to discover another planet that might sustain life as we know it. The next speaker, Dr. Chris McKay, is a planetary scientist at NASA Ames. He talked about the possibility of life on Mars or in some other solar system. He commented on the sameness of the origin of all life, and of the origin of, and the need for, oxygen and water. He believes that water originally came to Earth from comets. At least that is a viable possible source. Water might also have come to Earth via asteroids. Dr. McKay also postulates that there can be no water on Mars because Mars has no plate tectonic system, which he believes is an essential for recycling water. . Dr. Wes Huntress, NASA s Associate Administrator for Space Science, and Dr. Barbara Stone, also from NASA Headquarters, joined Drs. Cordova, Sargent and McKay in the question and answer period following the presentations. (Mr. Goldin was excused to keep an appointment with the President.) The discussion included the following statements and questions: The more missions that there are, the more technology is developed. We need to study our solar system to have something to which we can compare other systems. Before we send people to distant places or to other planets, we need to study the psychological and biological problems that are created by going away from Earth for a long period of time. Pulsars appear to have planets rotating around them. This is of interest and should be studied further. Looking back in time, is there any thought to seeing the development of life? How long did it take for oxygen to rise on the Earth? Do debris disks around the stars provide velocity patterns? To detect life scientists are listening for radio signals, looking for oxygen or ozone, and looking for liquid water. On Earth liquid water is the defining ecological parameter for life. This means that operationally the search for life elsewhere is primarily a search for liquid water.

Source record↗