 | |
| Author | Susan M. Gaines, Geoffrey Eglinton, and Jurgen Rullkotter |
|---|---|
| Language | English |
| Genre | Non-fiction |
| Publisher | Oxford University Press |
Publication date | 2008 |
| Pages | 376 |
| ISBN | 978-0-19-517619-3 |
Echoes of Life: What Fossil Molecules Reveal about Earth History is a book by Susan M. Gaines, Geoffrey Eglinton, and Jurgen Rullkotter concerning organic chemistry and, in particular, the links between the living and the material Earth. It was published by Oxford University Press in 2008.
Echoes of Life chronicles the history of the discipline of organic geochemistry. In early experiments, Alfred E. Treibs identified organic molecules, which he extracted from various samples, as chemically altered chlorophyll. He explained the chlorophyll as having come from plants that died millions of years ago. Since Treibs' discovery, thousands of biomarkers (a term coined 25 years after Treibs' discovery) have been identified. [1]
Chapter one, entitled Molecular Informants: A Changing Perspective of Organic Chemistry, gives a brief overview on the history of organic chemistry and explores the possibilities inherent in the science. It also describes how the authors first became interested in the subject and the work they have done within the field. [2]
Chapter two entitled Looking to the Rocks: Molecular Clues to the Origin of Life looks at the findings of Sir Robert Robinson and Melvin Calvin discoveries of organic compounds in petrol and the conversion of CO2 to organic molecules during photosynthesis. Early experiments had shown that organic compounds can form spontaneously under conditions similar to the pre-biotic era of earth. [3] These findings led to speculation on the possible discovery on the origins of life. The chapter ends with the authors saying as a precursor to the next chapter
If it was hard to resist the mystique and romance of three-billion-year-old rocks that might contain clues to the origin of life on Earth, it was even harder to resist a hunt for signs of life or its precursors on other planets—if only for the thrill of seeing and handling their rocks. [3]
Chapter three entitled From the Moon to Mars: The Search for Extraterrestrial Life. A Carbonaceous Meteorite which was found in Hungary in 1857, which was examined by Friedrich Wöhler was found to have organic compounds which he believed were Extraterrestrial in origin. The book moves on to Marcellin Berthelot who in 1864 claimed to have found "petroleum-like hydrocarbons" in a meteorite found near Orgueil. Louis Pasteur also ran experiments on this meteor and concluded it was sterile and not capable of generating life. The discovery of the Murchison meteorite also led to the finding of 70 amino acids most of which are not native to earth's biosphere. The authors look into the work done on samples brought back from the Apollo program missions. Geoffrey Eglinton one of the authors had been given a sample and although he knew there had never been life on the moon they had hoped to find organic compounds. None were found within those samples, which led to disappointment. These findings led the authors to speculate on the possibility of answering the question of whether there has ever been life on Mars and if future missions will bring back viable samples for testing. [4]
The book has received positive reviews in specialist scientific journals such as Astrobiology [5] and from the Astrobiology Society of Britain. [6]
Bill Green, writing in Chemical & Engineering News , called it "a remarkable book" and a "highly readable introduction to the field of organic geochemistry and that it also manages to capture the deep sense of curiosity and wonder associated with scientific investigation.". [7]
In BioScience , Karen Bushaw-Newton said that "those who are looking to broaden their knowledge of the connections between chemical compounds and the diversity of life, will find Echoes of Life well worth reading." [8]
Katherine H. Freeman writing for Science said that "the authors interweave an account of the development of biomarker research and sketches of what these fossil organic molecules tell us about the histories of Earth and life". [9]
Astrobiology is a scientific field within the life and environmental sciences that studies the origins, early evolution, distribution, and future of life in the universe through investigating its deterministic conditions and contingent events. As a discipline, astrobiology is founded on the premise that life may exist beyond Earth.
Hypothetical types of biochemistry are forms of biochemistry agreed to be scientifically viable but not proven to exist at this time. The kinds of living organisms currently known on Earth all use carbon compounds for basic structural and metabolic functions, water as a solvent, and DNA or RNA to define and control their form. If life exists on other planets or moons it may be chemically similar, though it is also possible that there are organisms with quite different chemistries – for instance, involving other classes of carbon compounds, compounds of another element, or another solvent in place of water.
Allan Hills 84001 (ALH84001) is a fragment of a Martian meteorite that was found in the Allan Hills in Antarctica on December 27, 1984, by a team of American meteorite hunters from the ANSMET project. Like other members of the shergottite–nakhlite–chassignite (SNC) group of meteorites, ALH84001 is thought to have originated on Mars. However, it does not fit into any of the previously discovered SNC groups. Its mass upon discovery was 1.93 kilograms (4.3 lb).
Pierre Eugène Marcellin Berthelot was a French chemist and Republican politician noted for the Thomsen–Berthelot principle of thermochemistry. He synthesized many organic compounds from inorganic substances, providing a large amount of counter-evidence to the theory of Jöns Jakob Berzelius that organic compounds required organisms in their synthesis. Berthelot was convinced that chemical synthesis would revolutionize the food industry by the year 2000, and that synthesized foods would replace farms and pastures. "Why not", he asked, "if it proved cheaper and better to make the same materials than to grow them?"
Cosmochemistry or chemical cosmology is the study of the chemical composition of matter in the universe and the processes that led to those compositions. This is done primarily through the study of the chemical composition of meteorites and other physical samples. Given that the asteroid parent bodies of meteorites were some of the first solid material to condense from the early solar nebula, cosmochemists are generally, but not exclusively, concerned with the objects contained within the Solar System.
The possibility of life on Mars is a subject of interest in astrobiology due to the planet's proximity and similarities to Earth. To date, no proof of past or present life has been found on Mars. Cumulative evidence suggests that during the ancient Noachian time period, the surface environment of Mars had liquid water and may have been habitable for microorganisms, but habitable conditions do not necessarily indicate life.
A biosignature is any substance – such as an element, isotope, or molecule – or phenomenon that provides scientific evidence of past or present life. Measurable attributes of life include its complex physical or chemical structures and its use of free energy and the production of biomass and wastes. A biosignature can provide evidence for living organisms outside the Earth and can be directly or indirectly detected by searching for their unique byproducts.
In 1976 two identical Viking program landers each carried four types of biological experiments to the surface of Mars. The first successful Mars landers, Viking 1 and Viking 2, then carried out experiments to look for biosignatures of microbial life on Mars. The landers each used a robotic arm to pick up and place soil samples into sealed test containers on the craft.
Geobiology is a field of scientific research that explores the interactions between the physical Earth and the biosphere. It is a relatively young field, and its borders are fluid. There is considerable overlap with the fields of ecology, evolutionary biology, microbiology, paleontology, and particularly soil science and biogeochemistry. Geobiology applies the principles and methods of biology, geology, and soil science to the study of the ancient history of the co-evolution of life and Earth as well as the role of life in the modern world. Geobiologic studies tend to be focused on microorganisms, and on the role that life plays in altering the chemical and physical environment of the pedosphere, which exists at the intersection of the lithosphere, atmosphere, hydrosphere and/or cryosphere. It differs from biogeochemistry in that the focus is on processes and organisms over space and time rather than on global chemical cycles.
Cholestane is a saturated tetracyclic triterpene. This 27-carbon biomarker is produced by diagenesis of cholesterol and is one of the most abundant biomarkers in the rock record. Presence of cholestane, its derivatives and related chemical compounds in environmental samples is commonly interpreted as an indicator of animal life and/or traces of O2, as animals are known for exclusively producing cholesterol, and thus has been used to draw evolutionary relationships between ancient organisms of unknown phylogenetic origin and modern metazoan taxa. Cholesterol is made in low abundance by other organisms (e.g., rhodophytes, land plants), but because these other organisms produce a variety of sterols it cannot be used as a conclusive indicator of any one taxon. It is often found in analysis of organic compounds in petroleum.
Extraterrestrial material refers to natural objects now on Earth that originated in outer space. Such materials include cosmic dust and meteorites, as well as samples brought to Earth by sample return missions from the Moon, asteroids and comets, as well as solar wind particles.
EXPOSE is a multi-user facility mounted outside the International Space Station (ISS) dedicated to astrobiology. EXPOSE was developed by the European Space Agency (ESA) for long-term spaceflights and was designed to allow exposure of chemical and biological samples to outer space while recording data during exposure.
The O/OREOS is a NASA automated CubeSat nanosatellite laboratory approximately the size of a loaf of bread that contains two separate astrobiology experiments on board. Developed by the Small Spacecraft Division at NASA Ames Research Center, the spacecraft was successfully launched as a secondary payload on STP-S26 led by the Space Test Program of the United States Air Force on a Minotaur IV launch vehicle from Kodiak Island, Alaska on 20 November 2010, at 01:25:00 UTC.
Susan M Gaines is an American writer. She is the author of the novels Accidentals (2020) and Carbon Dreams (2001), and co-author with Geoffrey Eglinton and Jurgen Rullkötter of the science book Echoes of Life: What Fossil Molecules Reveal about Earth History (2009). Her short stories have been nominated twice for the Pushcart Prize. She is a former fellow of the Hanse Institute for Advanced Study in Germany. In 2018, she was awarded a Suffrage Science Award for women in science and science writers who have inspired others.
Icebreaker Life is a Mars lander mission concept proposed to NASA's Discovery Program. The mission involves a stationary lander that would be a near copy of the successful 2008 Phoenix and InSight spacecraft, but would carry an astrobiology scientific payload, including a drill to sample ice-cemented ground in the northern plains to conduct a search for biosignatures of current or past life on Mars.
Zita Carla Torrão Pinto Martins, OSE, is a Portuguese astrobiologist, and an associate professor at Instituto Superior Técnico. She was a Royal Society University Research Fellow (URF) at Imperial College London. Her research explores how life may have begun on Earth by looking for organic compounds in meteorite samples.
OREOcube is an experiment designed by the European Space Agency (ESA) with the NASA that will investigate the effects of solar and cosmic radiation on selected organic compounds. It will consist in a 12-month orbital study of the effects of the outer space environment on astrobiologically relevant materials in an external exposure facility on the International Space Station (ISS).
The Mars Organic Molecule Analyser (MOMA) is a mass spectrometer-based instrument on board the Rosalind Franklin rover to be launched in 2028 to Mars on an astrobiology mission. It will search for organic compounds in the collected soil samples. By characterizing the molecular structures of detected organics, MOMA can provide insights into potential molecular biosignatures. MOMA will be able to detect organic molecules at concentrations as low as 10 parts-per-billion by weight (ppbw). MOMA examines solid crushed samples exclusively; it does not perform atmospheric analyses.
Pseudo-panspermia is a well-supported hypothesis for a stage in the origin of life. The theory first asserts that many of the small organic molecules used for life originated in space. It continues that these organic molecules were distributed to planetary surfaces, where life then emerged on Earth and perhaps on other planets. Pseudo-panspermia differs from the fringe theory of panspermia, which asserts that life arrived on Earth from distant planets.
Signs Of LIfe Detector (SOLID) is an analytical instrument under development to detect extraterrestrial life in the form of organic biosignatures obtained from a core drill during planetary exploration.