habitability Archives

Schematic illustration of the experimental workflow. (a) E. coli was incrementally adapted to increasing concentrations of NaClO4, NaCl and glycerol. (b) Example growth profiles of wild-type (WT) E. coli (grey) and after its adaptation and subsequent propagation at concentrations of 0.2 mol/kg NaClO4 (blue), 1.2 mol/kg NaCl (green) and 4 mol/kg glycerol (pink). Data represent means ± SD (n = 3). (c) The adaptive phenotypes were analyzed using proteomics. First, triplicates of each treatment and the WT were prepared, harvested during late exponential growth and analyzed by mass spectrometry. Next, we aimed to identify those adaptation mechanisms, which were specific for perchlorate-induced stress in E. coli. For this, a post hoc test (FDR ≤ 0.01) was performed, giving information on which treatment combinations significantly differ from each other for each protein. Sets of proteins for solute-specific and shared adaptation mechanisms were extracted using a strict filtering process and graphically depicted as Venn diagrams (see Materials and Methods). Lastly, the protein sets were used to identify significant adaptive pathways (FDR ≤ 0.05) using protein-protein interaction networks with the help of the STRING database42. Science Reports via PubMed

Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Extremeophiles and Extreme Environments, Habitable Zones, Mars, Status Report

Proteomic Insights Into Survival Strategies Of Escherichia Coli In Perchlorate-rich Martian Brines

by Keith CowingApril 4, 2025

Brines, potentially formed by the deliquescence and freezing point depression of highly hygroscopic salts, such as perchlorates (ClO4-), may allow for the spatial and temporal stability of liquid water on […]

Selected spectra of Teegarden’s star around the Hα line to demonstrate the line shape during quiescent phases and all flares. The spectra of activity level (1) are shown in green, of activity level (2) in blue, and of activity level (3) in red. The flare spectra are shown in magenta. There are a few spectra showing peculiar line shapes with broad additional line components either in absorption or emission (cyan lines). The dashed vertical line marks the central wavelength of Hα. The normalisation wavelength intervals are located well outside any broad wings at 6537.4–6547.9 and 6577.9–6586.4 Å. For the shown spectra the statistical errors are insignificant. -- astro-ph.SR

Astronomy & Telescopes, Imaging & Spectroscopy, Status Report

Coronal And Chromospheric Activity Of Teegarden’s Star

by Keith CowingApril 4, 2025September 18, 2025

Teegarden’s star is a late-type M-dwarf planet host, typically showing only rather low levels of activity. In this paper we present an extensive characterisation of this activity at photospheric, chromospheric, […]

Scatter plot of the flare energy as a function of spot group area for solar flares (black dots) and superflares of G-type stars from the Kepler sample by Okamoto et al. (2021). Left panel: Original Sun-like sample from Okamoto et al. (2021). Right panel: Updated solar observations based on the rescaling discussed in Hudson et al. (2024) (purple dots) and updated stellar sample utilizing the updated spot group area function by Herbst et al. (2021) (blue dots and according errors). -- astro-ph.SR

Astronomy & Telescopes, Atmospheres, Climate, Weather, Habitable Zones, Space Weather & Heliophysics, Status Report, Stellar Cartography

Comparing The Sun To Sun-like Stars. On The Importance Of Addressing Faculae/spot Domination

by Keith CowingApril 4, 2025April 4, 2025

Whether the Sun is an ordinary G-type star is still an open scientific question.

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report

Updating the Ephemeris and Physical Properties of Five Long-period Transiting Exoplanets Using TESS and CHEOPS

by Keith CowingApril 3, 2025April 3, 2025

The transiting long-period exoplanets are the most interesting follow-up targets for the next-generation instruments, using the most sophisticated observational techniques.

Schematic of a canonical habitable zone for terrestrial planets around main sequence stars. The inner and outer edges of the HZ, shown in blue, correspond to the moist greenhouse limit and the maximum greenhouse limit, respectively (Kasting et al., 1993; Kopparapu et al., 2013). The solar system planets and several exoplanets are shown for reference. Image Credits: Chester Harman.

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Extremeophiles and Extreme Environments, Gaia - Planetary Perspectives, Genomics, Proteomics, Bioinformatics, Habitable Zones, Status Report

Habitability and Biosignatures

by Keith CowingApril 1, 2025

The search for life beyond the solar system is a central goal in exoplanetary science. Exoplanet surveys are increasingly detecting potentially habitable exoplanets and large telescopes in space and on […]

Schematic diagram of the implications of microbial biofilms for astrobiology. Biofilms expand the habitability of microorganisms by shielding them from extreme conditions. This protective function is largely attributed to the EPS, which comprises exopolysaccharides, proteins, lipids, and e-DNA. In addition, biofilms are a promising source of biosignatures, as some components of EPS are highly resistant to degradation. EPS play a crucial role in biomineralization, the process by which microorganisms facilitate mineral formation, often in discrete and easily discriminated structures. The interactions between EPS and minerals further contribute to the preservation of these biopolymers, making them valuable indicators of microbial life on Earth and in extraterrestrial environments. -- Applied Environmental Microbiology

Analog Studies, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Fossils & Paleontology, Habitable Zones, Microbiology & Virology, Status Report

An Astrobiological Perspective on Microbial Biofilms: Their Importance for Habitability and Production of Detectable and Lasting Biosignatures

by Keith CowingMarch 29, 2025March 29, 2025

The search for life elsewhere in the universe has remained one of the main goals of astrobiological exploration.

Artist’s impression shows the planet K2-18b, its host star and an accompanying planet in this system. ESA/Hubble, M. Kornmesser

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Origin & Evolution of Life, Press Release, Water/Hycean Worlds & Oceanography

Atmospheres Of New Planets Might Have Unexpected Mixtures Of Hydrogen And Water

by Keith CowingMarch 28, 2025March 28, 2025

Recent studies show that the most common type of planets in our galaxy, those between the sizes of Earth and Neptune, typically form with a hydrogen atmosphere, resulting in conditions […]

(a) Visualization of statistical effects of the highly predictive biosignature features using a Regression-based Association-Interaction Network (RAIN) with node numbers in order of NPDR-LURF importance. RAIN encodes feature main effects and statistical interactions in a network. Nodes 2, 3, 4, and 5 have the largest main effects. For nodes 2 and 4, the main effect increases the probability of an abiotic class prediction. The TS feature diff2_acff1 is also a hub in the interaction network, participating in three large interactions with nodes 2, 3, and 5 that influence the probability for both biotic and abiotic predictions. (b) The Random Forest classifier trained on NPDR-LURF features for biosignatures yields a training accuracy of 87.9%, trained on a sample size m = 140. Dark gray and green diagonals represent the number of correct predictions: 81/89 abiotic samples are correctly classified, and 42/51 biotic samples are correctly classified. The precision for biotic samples in the training data is 0.824 and the recall is 0.84. (c) The same classifier yields a high test accuracy of 88.2%: 20/22 abiotic samples are correctly classified, and 10/12 biotic samples are correctly classified. The biotic precision for the test data is 0.833 and the recall is also 0.833. -- Earth and Space Science

Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Habitable Zones, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

Interpretable Machine Learning Biosignature Detection From Ocean Worlds Analogue CO2 Isotopologue Data

by Keith CowingMarch 25, 2025March 25, 2025

Future missions to icy ocean worlds (OW) such as Europa and Enceladus will evaluate the habitability and potential for biosignatures on these worlds.

Population-level predictions of gas dwarf and water world hypotheses for sub-Neptune evolution in the left and right-hand panels, respectively. The populations are shown at times of 1 − 10 Gyrs and < 40 Myrs in the top and bottom panels, respectively. Colour bars represent relative probability of planet occurrence. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Distinguishing Between Gas Dwarfs And Water Worlds With Young Transiting Exoplanets

by Keith CowingMarch 25, 2025April 15, 2025

The detection of young transiting exoplanets represents a new frontier in our understanding of planet formation and evolution.

An active region on the sun emitted a mid-level solar flare, peaking at 4:47 a.m. EST on Nov. 5, 2014. This is the second mid-level flare from the same active region, labeled AR 12205, which rotated over the left limb of the sun on Nov. 3. -- NASA

Astronomy & Telescopes, Habitable Zones, Radiation, Space Weather & Heliophysics, Status Report, Stellar Cartography

Analyzing the Morphology of Late-phase Stellar Flares From G-, K-, and M-type Stars

by Keith CowingMarch 24, 2025March 24, 2025

Stellar flares occasionally present a peak-bump light curve morphology, consisting of an initial impulsive phase followed by a gradual late phase. Analyzing this specific morphology can uncover the underlying physics […]

habitability

Proteomic Insights Into Survival Strategies Of Escherichia Coli In Perchlorate-rich Martian Brines

Coronal And Chromospheric Activity Of Teegarden’s Star

Comparing The Sun To Sun-like Stars. On The Importance Of Addressing Faculae/spot Domination

Updating the Ephemeris and Physical Properties of Five Long-period Transiting Exoplanets Using TESS and CHEOPS

Habitability and Biosignatures

An Astrobiological Perspective on Microbial Biofilms: Their Importance for Habitability and Production of Detectable and Lasting Biosignatures

Atmospheres Of New Planets Might Have Unexpected Mixtures Of Hydrogen And Water

Interpretable Machine Learning Biosignature Detection From Ocean Worlds Analogue CO2 Isotopologue Data

Distinguishing Between Gas Dwarfs And Water Worlds With Young Transiting Exoplanets

Analyzing the Morphology of Late-phase Stellar Flares From G-, K-, and M-type Stars

Astrobiologist Dale Andersen’s Antarctic Field Report: Wheels Down In Cape Town

NASA Spaceline Current Awareness List #1,221 16 October 2026 (Space Life Science Research Results)

SwRI Staff Contribute To New Ideas About Origins Of Uranus And Neptune

A Voyage Into The Slow-motion World Of Earth’s Deep Seas

Rosalind Franklin Rover Stand-In Tackles A Tilted Descent