Extraterrestrial life in the Solar System?

2008 ◽  
pp. 71-86
Keyword(s):  
Solar System ◽  
Extraterrestrial Life

Prospects for Life on Other Planets

2019 ◽  
Author(s):  
David W. Deamer
Keyword(s):  
Solar System ◽  
Origin Of Life ◽  
Hydrothermal Vents ◽  
European Space Agency ◽  
Extraterrestrial Life ◽  
Major Question ◽  
Space Agency ◽  
Planetary Bodies ◽  
The Origin Of Life ◽  
Alternative Scenarios

This book describes a hypothetical process in which populations of protocells can spontaneously assemble and begin to grow and proliferate by energy- dependent polymerization. This might seem to be just an academic question pursued by a few dozen researchers as a matter of curiosity, but in the past three decades advances in engineering have reached a point where both NASA and the European Space Agency (ESA) routinely send spacecraft to other planetary objects in our solar system. A major question being pursued is whether life has emerged elsewhere than on Earth. The limited funds available to support such missions require decisions to be made about target priorities that are guided by judgment calls. These in turn depend on plausible scenarios related to the origin of life on habitable planetary surfaces. We know that other planetary bodies in our solar system have had or do have conditions that would permit microbial life to exist and perhaps even to begin. By a remarkable coincidence, the two most promising objects for extraterrestrial life happen to represent the two alternative scenarios described in this book: An origin of life in conditions of hydrothermal vents or an origin in hydrothermal fields. This final chapter will explore how these alternative views can guide our judgment about where to send future space missions designed as life-detection missions. Questions to be addressed: What is meant by habitability? Which planetary bodies are plausible sites for the origin of life? How do the hypotheses described in this book relate to those sites? There is healthy public interest in how life begins and whether it exists elsewhere in our solar system or on the myriad exoplanets now known to orbit other stars. This has fueled a series of films, television programs, and science fiction novels. Most of these feature extrapolations to intelligent life but a few, such as The Andromeda Strain, explore what might happen if a pathogenic organism from space began to spread to the human population. There is a serious and sustained scientific effort—SETI, or Search for Extraterrestrial Intelligence—devoted to finding an answer to this question.

scholarly journals Six ‘Must-Have’ Minerals for Life’s Emergence: Olivine, Pyrrhotite, Bridgmanite, Serpentine, Fougerite and Mackinawite

Life ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 291
Author(s):  
Michael Russell ◽  
Adrian Ponce
Keyword(s):  
Free Energy ◽  
Solar System ◽  
Internal Pressure ◽  
Electron Acceptors ◽  
Extraterrestrial Life ◽  
Apparent Absence ◽  
Essential Requirement ◽  
Dissipative Processes ◽  
Planetary Bodies ◽  
Internal Pressures

Life cannot emerge on a planet or moon without the appropriate electrochemical disequilibria and the minerals that mediate energy-dissipative processes. Here, it is argued that four minerals, olivine ([Mg>Fe]2SiO4), bridgmanite ([Mg,Fe]SiO3), serpentine ([Mg,Fe,]2-3Si2O5[OH)]4), and pyrrhotite (Fe(1−x)S), are an essential requirement in planetary bodies to produce such disequilibria and, thereby, life. Yet only two minerals, fougerite ([Fe2+6xFe3+6(x−1)O12H2(7−3x)]2+·[(CO2−)·3H2O]2−) and mackinawite (Fe[Ni]S), are vital—comprising precipitate membranes—as initial “free energy” conductors and converters of such disequilibria, i.e., as the initiators of a CO2-reducing metabolism. The fact that wet and rocky bodies in the solar system much smaller than Earth or Venus do not reach the internal pressure (≥23 GPa) requirements in their mantles sufficient for producing bridgmanite and, therefore, are too reduced to stabilize and emit CO2—the staple of life—may explain the apparent absence or negligible concentrations of that gas on these bodies, and thereby serves as a constraint in the search for extraterrestrial life. The astrobiological challenge then is to search for worlds that (i) are large enough to generate internal pressures such as to produce bridgmanite or (ii) boast electron acceptors, including imported CO2, from extraterrestrial sources in their hydrospheres.

scholarly journals The search for microbial Martian life and American Buddhist ethics

2019 ◽  
Vol 19 (3) ◽  
pp. 244-252 ◽  
Author(s):  
Daniel Capper
Keyword(s):  
Solar System ◽  
Qualitative Analysis ◽  
Space Research ◽  
Buddhist Ethics ◽  
Extraterrestrial Life ◽  
Life On Mars

AbstractMultiple searches hunt for extraterrestrial life, yet the ethics of such searches in terms of fossil and possible extant life on Mars have not been sufficiently delineated. In response, in this essay, I propose a tripartite ethic for searches for microbial Martian life that consists of default non-harm towards potential living beings, default non-harm to the habitats of potential living beings, but also responsible, restrained scientific harvesting of some microbes in limited transgression of these default non-harm modes. Although this multifaceted ethic remains secular and hence adaptable to space research settings, it arises from both a qualitative analysis of authoritative Buddhist scriptural ethics as well as the quantified ethnographic survey voices of contemporary American Buddhists. The resulting tripartite ethic, while developed for Mars, contains ramifications for the study of microbes on Earth and further retains application to other research locations in our Solar system.

Conclusion

2013 ◽  
Author(s):  
Andrew P. Ingersoll
Keyword(s):  
Solar System ◽  
Giant Planets ◽  
Outer Solar System ◽  
The Sun ◽  
Extraterrestrial Life ◽  
Better Than

This concluding chapter discusses some of the lessons that can be learned from studying the planets and planetary climates. It first considers the general principles that turned out to be right; for example, size and distance from the Sun matter. The larger objects are able to hold on to their atmospheres better than the small objects. The outer solar system is hydrogen rich and the inner solar system is oxygen rich; as one moves away from the Sun different substances take on different roles. There are also assumptions that proved inaccurate; such was the case for Venus, Mars, and the moons of the giant planets. The chapter also asks whether the study of planetary climates provides lessons for Earth, whether the study of planets has informed us about the likelihood of extraterrestrial life, and whether it has made the development of extraterrestrial life seem more likely.

scholarly journals Classification of the Biogenicity of Complex Organic Mixtures for the Detection of Extraterrestrial Life

Life ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 234
Author(s):  
Nicholas Guttenberg ◽  
Huan Chen ◽  
Tomohiro Mochizuki ◽  
H. James Cleaves
Keyword(s):  
Solar System ◽  
Extraterrestrial Life ◽  
Analytical Technique ◽  
Spectral Signatures ◽  
Organic Mixtures ◽  
Terrestrial Life ◽  
Algorithmic Analysis ◽  
In Situ Methods ◽  
Solar System Exploration ◽  
Near Future

Searching for life in the Universe depends on unambiguously distinguishing biological features from background signals, which could take the form of chemical, morphological, or spectral signatures. The discovery and direct measurement of organic compounds unambiguously indicative of extraterrestrial (ET) life is a major goal of Solar System exploration. Biology processes matter and energy differently from abiological systems, and materials produced by biological systems may become enriched in planetary environments where biology is operative. However, ET biology might be composed of different components than terrestrial life. As ET sample return is difficult, in situ methods for identifying biology will be useful. Mass spectrometry (MS) is a potentially versatile life detection technique, which will be used to analyze numerous Solar System environments in the near future. We show here that simple algorithmic analysis of MS data from abiotic synthesis (natural and synthetic), microbial cells, and thermally processed biological materials (lab-grown organisms and petroleum) easily identifies relational organic compound distributions that distinguish pristine and aged biological and abiological materials, which likely can be attributed to the types of compounds these processes produce, as well as how they are formed and decompose. To our knowledge this is the first comprehensive demonstration of the utility of this analytical technique for the detection of biology. This method is independent of the detection of particular masses or molecular species samples may contain. This suggests a general method to agnostically detect evidence of biology using MS given a sufficiently strong signal in which the majority of the material in a sample has either a biological or abiological origin. Such metrics are also likely to be useful for studies of possible emergent living phenomena, and paleobiological samples.

scholarly journals Organic chemistry in space and the search for life in our Solar System 

2021 ◽  
Author(s):  
Pascale Ehrenfreund
Keyword(s):  
Solar System ◽  
United Arab Emirates ◽  
Space Missions ◽  
Planetary Science ◽  
Laboratory Research ◽  
Polar Regions ◽  
Extraterrestrial Life ◽  
Solar Ultraviolet Radiation ◽  
Hayabusa 2 ◽  
Human Exploration

<p>One of the most fascinating questions in planetary science is how life originated on Earth and whether life exists beyond Earth. Life on Earth originated approximately 3.5 billion years ago and has adapted to nearly every explored environment including the deep ocean, dry deserts and ice continents. What were the chemical raw materials available for life to develop? Many carbonaceous compounds are identified by astronomical observations in our Solar System and beyond. Small Solar System bodies hold clues to both processes that formed our Solar System and the processes that probably contributed carbonaceous molecules and volatiles during the heavy bombardment phase to the young planets in our Solar System. The latter process may have contributed to life’s origin on Earth. Space missions that investigate the composition of comets and asteroids and in particular their organic content provide major opportunities to determine the prebiotic reservoirs that were available to early Earth and Mars. Recently, the Comet rendezvous mission Rosetta has monitored the evolution of comet 67P/Churyumov-Gerasimenko during its approach to the Sun. Rosetta observed numerous volatiles and complex organic compounds on the cometary surface and in the coma. JAXA’s Hayabusa-2 mission has returned samples from near-Earth asteroid Ryugu in December 2020 and we may have some interesting scientific results soon. Hayabusa-2 also carried the German-French landing module MASCOT (mobile asteroid surface scout) that provided new insights into the structure and composition of the asteroid Ryugu during its 17-hour scientific exploration.</p><p>Presently, a fleet of robotic space missions target planets and moons in order to assess their habitability and to seek biosignatures of simple extraterrestrial life beyond Earth. Prime future targets in the outer Solar System include moons that may harbor internal oceans such as Europa, Enceladus, and Titan. Life may have emerged during habitable periods on Mars and evidence of life may still be preserved in the subsurface, evaporite deposits, caves, or polar regions. On Mars, a combination of solar ultraviolet radiation and oxidation processes are destructive to organic material and life on and close to the surface. However, the progress and the revolutionary quality and quantity of data on “extreme life” on Earth has transformed our view of habitability. In 2021, we will hopefully have three robotic missions arriving at Mars from China, the United Arab Emirates and NASA (Tianwen-1, Hope, and Mars2020 respectively). In 2022, ESA’s ExoMars program will launch the Rosalind Franklin Rover and landing platform, and drill two meters deep into the Martian subsurface for the first time. Mars is still the central object of interest for habitability studies and life detection beyond Earth, paving the way for returned samples and human exploration.</p><p>Measurements from laboratory, field, and space simulations are vital in the preparation phase for future planetary exploration missions. This Cassini lecture will review the evolution and distribution of organic matter in space, including results from space missions, field and laboratory research, and discuss the science and technology preparation necessary for robotic and human exploration efforts investigating habitability and biosignatures in our Solar System.</p>

Leaves, genes, and greenhouse gases

2007 ◽  
Author(s):  
David Beerling
Keyword(s):  
Solar System ◽  
Liquid Water ◽  
Natural Radioactivity ◽  
Extraterrestrial Life ◽  
Left Behind ◽  
Direct Observations ◽  
Solar System Exploration ◽  
Life On Earth ◽  
The Universe ◽  
Modern Astronomy

The Galileo spacecraft, named after the Italian astronomer Galileo Galilei (1564–1642), who launched modern astronomy with his observations of the heavens in 1610, plunged to oblivion in Jupiter’s crushing atmosphere on 21 September 2003. Launched in 1989, it left behind a historic legacy that changed the way we view the solar system. Galileo’s mission was to study the planetary giant Jupiter and its satellites, four of which Galileo himself observed, to his surprise, moving as ‘stars’ around the planet from his garden in Pardu, Italy. En route, the spacecraft captured the first close-up images of an asteroid (Gaspra) and made direct observations of fragments of the comet Shoemaker–Levy 9 smashing into Jupiter. Most remarkable of all were the startling images of icebergs on the surface of Europa beamed backed in April 1997, after nearly eight years of solar system exploration. Icebergs suggested the existence of an extraterrestrial ocean, liquid water. To the rapt attention of the world’s press, NASA’s mission scientists commented that liquid water plus organic compounds already present on Europa, gave you ‘life within a billion years’. Whether this is the case is a moot point; water is essential for life on Earth as we know it, but this is no guarantee it is needed for life elsewhere in the Universe. Oceans may also exist beneath the barren rocky crusts of two other Galilean satellites, Callisto and Ganymede. Callisto and Ganymede probably maintain a liquid ocean thanks to the heat produced by natural radioactivity of their rocky interiors. Europa, though, lies much closer to Jupiter, and any liquid water could be maintained by heating due to gravitational forces that stretch and squeeze the planet in much the same way as Earth’s moon influences our tides. To reach Jupiter, Galileo required two slingshots (gravitational assists) around Earth and Venus. Gravitational assists accelerate the speed and adjust the trajectory of the spacecraft without it expending fuel. The planets doing the assisting pay the price with an imperceptible slowing in their speed of rotation. In Galileo’s case, the procedure fortuitously permitted close observations of Earth from space, allowing a control experiment in the search for extraterrestrial life, never before attempted.

scholarly journals Commission 51: Bioastronomy – Search for Extraterrestrial Life

2005 ◽  
Vol 1 (T26A) ◽  
pp. 171-174
Author(s):  
Karen Meech ◽  
Alan Boss ◽  
Cristiano Cosmovici ◽  
Pascale Ehrenfreund ◽  
David Latham ◽  
...  
Keyword(s):  
Solar System ◽  
Origin Of Life ◽  
International Society ◽  
International Organizations ◽  
Extrasolar Planets ◽  
Extraterrestrial Life ◽  
Evolution Of Life ◽  
Formation And Evolution ◽  
The Origin Of Life ◽  
Life On Earth

Historically, there have been two main groups dealing with the investigation of extraterrestrial life and habitable worlds. The first is IAU Commission 51, composed of astronomers, physicists and engineers who focus on the search for extrasolar planets, formation and evolution of planetary systems, and the astronomical search for intelligent signals. The second group, the International Society for the Study of the Origin of Life (ISSOL), is composed largely of biologists and chemists focusing research on the biogenesis and evolution of life on Earth and in the solar system. There are now a variety of international organizations dedicated to this field, and this triennium has seen the beginnings of coordination and interaction between the groups through the Federation of Astrobiology Organizations, FAO.

Hydrogen, Hydrocarbons, and Habitability Across the Solar System

Elements ◽  
2020 ◽  
Vol 16 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Christopher R. Glein ◽  
Mikhail Yu. Zolotov
Keyword(s):  
Solar System ◽  
Great Lakes ◽  
Liquid Water ◽  
Molecular Hydrogen ◽  
Organic Molecules ◽  
Extraterrestrial Life ◽  
Volatile Elements ◽  
Reducing Conditions ◽  
Future Space ◽  
Reduction Of Co2

The ingredients to make an environment habitable (e.g., liquid water, chemical disequilibria, and organic molecules) are found throughout the solar system. Liquid water has existed transiently on some bodies and persistently as oceans on others. Molecular hydrogen occurs in a plume on Saturn’s moon Enceladus. It can drive the reduction of CO2 to release energy. Methane has been observed in many places: from the dusty plains of Mars, to the great lakes of the Saturnian moon Titan, to the glacial wonderland that is Pluto. Organic molecules are common where volatile elements and reducing conditions prevail: these organic molecules can have diverse origins. Future space missions will attempt to illuminate the “organic solar system” and the role played by possible extraterrestrial life.

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