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| Open AccessHigh-spatial resolution functional chemistry of nitrogen compounds in the observed UK meteorite fall Winchcombe
Important biomolecules from the birth of our Solar System such as amino acids and polyaromatic hydrocarbons were analysed in the UK meteorite fall Winchcombe by synchrotron and electron microscopy techniques with unique high energy resolution.
- Christian Vollmer
- , Demie Kepaptsoglou
- & Quentin M. Ramasse
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| Open AccessA new era in solar system astronomy with JWST
The exploration of our solar system is being radically changed since the beginning of operations of the James Webb Space Telescope (JWST) in mid 2022. JWST’s extraordinary sensitivity and instrumentation allow for sensitive searches for the building blocks of life and to test for habitability, also enabling new discoveries on small bodies to giant planets across our solar system and beyond.
- G. L. Villanueva
- & S. N. Milam
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| Open AccessUncovering the chiral bias of meteoritic isovaline through asymmetric photochemistry
Excess of l-amino acids in meteorites suggests an extraterrestrial origin of biomolecular homochirality, which may stem from chiral light-matter interactions. Here the authors support this hypothesis with asymmetric photolysis experiments on racemic isovaline films, showing that circularly polarized starlight can produce l-enantiomeric excesses that can be amplified during parent bodies’ alteration.
- Jana Bocková
- , Nykola C. Jones
- & Cornelia Meinert
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| Open AccessRyugu asteroid sample return provides a natural laboratory for primordial chemical evolution
The samples returned from near-Earth asteroid (162173) Ryugu provide a pristine record of the 4.6 billion years since the birth of the Solar System. The Hayabusa2 initial analysis team has integrated a range of analytical techniques to investigate Ryugu’s organic chemistry. Here, we highlight their latest findings, the potential questions which may be answered, and provide an overview of new prospects in the decade to come.
- Yasuhiro Oba
- , Yoshinori Takano
- & Hiroshi Naraoka
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| Open AccessPhosphate availability and implications for life on ocean worlds
Is phosphorous a limiting factor for life on ocean worlds (e.g. Europa and Enceladus)? Calculated dissolved phosphate concentrations from a wide range of possible water-rock reactions suggest cell populations larger than those observed in Earth’s deep oceans could be supported.
- Noah G. Randolph-Flagg
- , Tucker Ely
- & Tori M. Hoehler
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| Open AccessMetal-rich stars are less suitable for the evolution of life on their planets
Low stellar ultraviolet (UV) radiation leads to low ozone abundances, therefore, less planetary UV protection. Here, the authors show that planets in the habitable zones of metal-poor stars, despite their higher UV radiation than metal-rich stars, are the best targets for search for life.
- Anna V. Shapiro
- , Christoph Brühl
- & Jos Lelieveld
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| Open AccessHabitability and sub glacial liquid water on planets of M-dwarf stars
A long-standing issue in astrobiology is whether planets orbiting the most abundant type of stars, M-dwarfs, can support liquid water and eventually life. A new study shows that subglacial melting may provide an answer, significantly extending the habitability region, in particular around M-dwarf stars, which are also the most promising for biosignature detection with the present and near-future technology.
- Amri Wandel
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| Open AccessVolcanic Island lightning prebiotic chemistry and the origin of life in the early Hadean eon
The early Hadean eon (>4Ga) may have had a periodically ice-covered global ocean and limited subaerial landmass, and this could have resulted in infrequent lightning occurrence. This infrequency of lightning may have limited the synthesis of prebiotic compounds necessary for life’s origins. Here I present a hypothesis that lightning associated with volcanic island eruptions created focal points for the generation of prebiotic ingredients and ultimately the origin of life.
- Jeffrey L. Bada
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| Open AccessUracil in the carbonaceous asteroid (162173) Ryugu
Uracil was identified in the sample returned from the asteroid Ryugu. Having been provided to the early Earth as a component in such asteroidal materials, these molecules might have played a role for prebiotic chemical evolution on the early Earth
- Yasuhiro Oba
- , Toshiki Koga
- & Yuichi Tsuda
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| Open AccessInsights into the formation and evolution of extraterrestrial amino acids from the asteroid Ryugu
Amino acid concentrations from 2 particles returned from different touchdown sites on the surface of Ryugu are reported. Differences in chemistry suggest different levels of aqueous alteration are recorded at the 2 sampled locations.
- Christian Potiszil
- , Tsutomu Ota
- & Eizo Nakamura
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| Open AccessLife on Mars, can we detect it?
Searching for evidence of life on Mars is a major impetus for exploration. A new study published in Nature Communications finds that current Mars mission instruments lack the essential sensitivity to identify life traces in Chilean desert samples that strongly resemble the martian area currently under study by NASA’s Perseverance rover.
- Carol R. Stoker
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| Open AccessDark microbiome and extremely low organics in Atacama fossil delta unveil Mars life detection limits
Unique microorganisms of a fossil river delta in the Atacama Desert unveil the current limits of life detection on Mars.
- Armando Azua-Bustos
- , Alberto G. Fairén
- & Elizabeth Rampe
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| Open AccessVolcanically hosted venting with indications of ultramafic influence at Aurora hydrothermal field on Gakkel Ridge
The Aurora hydrothermal field (Arctic Ocean) is hosted in volcanic rocks but also shows evidence of mantle rock influence in the shallow sub-surface. Our discovery is pertinent to disciplines from marine mining to the search for life beyond Earth.
- Christopher R. German
- , Eoghan P. Reeves
- & Antje Boetius
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| Open AccessLow 13C-13C abundances in abiotic ethane
Distinguishing biotic compounds from abiotic ones is critical to the search for life in the universe. Here, the authors demonstrate that the abiotic ethane has distinctively low 13C-13C abundances compared to biotic ethane.
- Koudai Taguchi
- , Alexis Gilbert
- & Yuichiro Ueno
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| Open AccessGeoelectrochemistry-driven alteration of amino acids to derivative organics in carbonaceous chondrite parent bodies
Researchers at Earth-Life Science Institute (ELSI) discovered a chemical process that can explain the very low amino acid abundances in aqueously altered carbonaceous chondrites, deepening our understanding on the Solar System chemical evolution.
- Yamei Li
- , Norio Kitadai
- & Kristin Johnson-Finn
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| Open AccessProposed energy-metabolisms cannot explain the atmospheric chemistry of Venus
The metabolisms proposed for hypothetical life in the clouds of Venus cannot explain the planet’s atmospheric chemistry and thus a limit can be placed on the maximum allowed biomass.
- Sean Jordan
- , Oliver Shorttle
- & Paul B. Rimmer
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| Open AccessIdentifying the wide diversity of extraterrestrial purine and pyrimidine nucleobases in carbonaceous meteorites
All DNA/RNA nucleobases were identified in carbonaceous meteorites. Having been provided to the early Earth as a component in carbonaceous meteorites, these molecules might have played a role for the emergence of genetic functions in early life.
- Yasuhiro Oba
- , Yoshinori Takano
- & Hiroshi Naraoka
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| Open AccessIdentifying molecules as biosignatures with assembly theory and mass spectrometry
The search for life in the universe is difficult due to issues with defining signatures of living systems. Here, the authors present an approach based on the molecular assembly number and tandem mass spectrometry that allows identification of molecules produced by biological systems, and use it to identify biosignatures from a range of samples, including ones from outer space.
- Stuart M. Marshall
- , Cole Mathis
- & Leroy Cronin
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| Open AccessOxygen suppression of macroscopic multicellularity
The evolution of multicellular life is hypothesized to have been promoted by rising oxygen levels. Through experimental evolution and modeling, Bozdag et al. demonstrate that our planet’s first oxygenation would have strongly constrained, not promoted, the evolution of multicellular life.
- G. Ozan Bozdag
- , Eric Libby
- & William C. Ratcliff
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| Open AccessLightning strikes as a major facilitator of prebiotic phosphorus reduction on early Earth
Determining the origins of life on Earth is confounded by the fact that the sources of nutrients necessary to create early life forms remain mysterious. Here the authors show that lightning strikes could have supplied a major source of essential phosphorus on early Earth.
- Benjamin L. Hess
- , Sandra Piazolo
- & Jason Harvey
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| Open AccessExtraterrestrial hexamethylenetetramine in meteorites—a precursor of prebiotic chemistry in the inner solar system
This manuscript tackles the origin of organic molecules in carbonaceous meteorites. Identifying hexamethylenetetramine in three carbonaceous meteorites, the authors propose formation from ammonia and formaldehyde by photochemical and thermal reactions in the interstellar medium, followed by the incorporation into planetary systems.
- Yasuhiro Oba
- , Yoshinori Takano
- & Shogo Tachibana
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| Open AccessCarbonate-silicate cycle predictions of Earth-like planetary climates and testing the habitable zone concept
In the habitable zone concept, a planet’s carbon dioxide-water greenhouse maintains surface liquid water. Here, the authors estimate how many Earthlike exoplanets are needed to detect a relationship between stellar flux and the atmospheric carbon dioxide predicted by carbon cycle modeling.
- Owen R. Lehmer
- , David C. Catling
- & Joshua Krissansen-Totton
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| Open AccessSpace station biomining experiment demonstrates rare earth element extraction in microgravity and Mars gravity
Rare earth elements are used in electronics, but increase in demand could lead to low supply. Here the authors conduct experiments on the International Space Station and show microbes can extract rare elements from rocks at low gravity, a finding that could extend mining potential to other planets.
- Charles S. Cockell
- , Rosa Santomartino
- & René Demets
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| Open AccessPolypeptide formation in clusters of β-alanine amino acids by single ion impact
Formation of peptide bonds in cold gas-phase environments might represent a prebiotic synthesis route of polypeptides. Here, the authors show the formation of up to tetra-peptide species in the collision of He2+ ions, with kinetic energies typical for solar wind ions, with cold β-alanine clusters.
- Patrick Rousseau
- , Dariusz G. Piekarski
- & Bernd A. Huber
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| Open AccessIn-situ preservation of nitrogen-bearing organics in Noachian Martian carbonates
Mars has long been thought to contain organic compounds, but the origins and plausibility are debated. Here the authors employ a new technique to assess organic nitrogen compounds in a Martian meteorite, concluding that these compounds are indeed likely to originate from the Red Planet.
- Mizuho Koike
- , Ryoichi Nakada
- & Atsuko Kobayashi
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| Open AccessMinimal biomass deposition in banded iron formations inferred from organic matter and clay relationships
Banded iron formations could have formed in the early oceans due to microbial metabolism. Here Dodd and colleagues find little organic carbon in these formations, indicating microbial iron cycling was minimal and could have limited the recycling of important nutrients to overlying waters.
- Matthew S. Dodd
- , Dominic Papineau
- & Juha A. Karhu
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| Open AccessNucleobase synthesis in interstellar ices
The formation of nucleobases can take place in extraterrestrial environments. Here the authors show the simultaneous synthesis of three purine nucleobases and three pyrimidine from interstellar ice analogues that suggest the evolution from molecular clouds to stars and planets provide suitable environment for nucleobase synthesis in space.
- Yasuhiro Oba
- , Yoshinori Takano
- & Akira Kouchi
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| Open AccessOrganometallic compounds as carriers of extraterrestrial cyanide in primitive meteorites
Cyanide is thought to be crucial for the origin of life. Here, the authors showed that iron cyanocarbonyl complexes are present in meteorites and propose that these compounds were a source of free cyanide on early Earth and served as precursors to the active sites of ancient hydrogenases.
- Karen E. Smith
- , Christopher H. House
- & Michael P. Callahan
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| Open AccessReduction spheroids preserve a uranium isotope record of the ancient deep continental biosphere
Red beds contain reduction spheroids that formed underground millions of years ago and whose origin remains poorly constrained. Here the authors use uranium isotopes to identify ancient fingerprints of bacteria in these features, confirming that they were produced by subsurface life in the geological past.
- Sean McMahon
- , Ashleigh v. S. Hood
- & Stephen Bowden
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| Open AccessBiological methane production under putative Enceladus-like conditions
Many methanogenic archaea use H2 and CO2 to produce methane. Here, Taubner et al. show that Methanothermococcus okinawensis produces methane under conditions extrapolated for Saturn’s icy moon, Enceladus, and estimate that serpentinization may produce sufficient H2 for biological methane production.
- Ruth-Sophie Taubner
- , Patricia Pappenreiter
- & Simon K.-M. R. Rittmann
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| Open AccessHighly compressed water structure observed in a perchlorate aqueous solution
Significant amounts of different perchlorate salts have been discovered on the surface of Mars. Here, the authors show that magnesium perchlorate has a major impact on water structure in solution, providing insight into how an aqueous fluid might exist under the sub-freezing conditions present on Mars.
- Samuel Lenton
- , Natasha H. Rhys
- & Lorna Dougan
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| Open AccessAncient hydrothermal seafloor deposits in Eridania basin on Mars
The Eridania basin on Mars was once the site of a vast inland sea. Here, the authors show that the most ancient materials in the Eridania basin were formed in a deep-water hydrothermal setting and may be an analogue for early environmental conditions on Earth.
- Joseph R. Michalski
- , Eldar Z. Noe Dobrea
- & Javier Cuadros
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| Open AccessClimate variations on Earth-like circumbinary planets
Large variations in insolation experienced by circumbinary planets raise the question of the habitability of such planets. Here, the authors show that while the changing insolation does not radically affect habitability, it does impact on the planet’s climate and on the interpretation of future observations.
- Max Popp
- & Siegfried Eggl
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| Open AccessEvidence for methane in Martian meteorites
Extremophiles on Earth are known to respire methane, and the potential existence of methane on Mars indicates similar organisms could survive there. Here, the authors present data from Martian meteorites confirming the presence of methane, indicating that a habitat capable of supporting organisms exists on Mars.
- Nigel J. F. Blamey
- , John Parnell
- & Roberta L. Flemming