habitability Archives

An artist’s impression of the proposed VERVE mission to Venus the answer whether tiny bacterial lifeforms really do exist in the planet’s clouds. Credit Danielle Futselaar Licence type Attribution (CC BY 4.0)

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Habitable Zones, Imaging & Spectroscopy, Missions & Hardware, Press Release, Venus

The Venus Explorer for Reduced Vapours in the Environment (VERVE)

by Keith CowingJuly 10, 2025July 10, 2025

The answer to whether tiny bacterial lifeforms really do exist in the clouds of Venus could be revealed once-and-for-all by a UK-backed mission.

Earth's limb as seen from space. Photo ISS001-421-24 3 March 2001 Larger image -- NASA

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

A Statistical Method For Constraining the Capability of the Habitable Worlds Observatory to Understand Ozone Onset Time in Earth Analogs

by Keith CowingJuly 9, 2025July 9, 2025

The oxygenation of Earth’s atmosphere 2.3 billion years ago, which on exoplanets is expected to be most detectable via the UV ozone feature at ∼0.25 μm, is often regarded as […]

A schematic of four observing programs (science cases) proposed in this HWO science case to discover and characterize life beyond Earth. -- astro-ph.EP

Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Imaging & Spectroscopy, Origin & Evolution of Life, Plant Biology, Press Release, Water/Hycean Worlds & Oceanography

Detecting Alien Living Worlds And Photosynthetic Life Using Imaging Polarimetry With The HWO Coronagraph

by Keith CowingJuly 8, 2025July 8, 2025

Our Earth, being the only living planet that we know, provides us with clues that photosynthetic life-forms may be dominant on other exoplanets for billions of years.

Distribution of 339 planets in the stellar effective flux (𝑆eff) versus stellar temperature (𝑇eff) space. Red solid circles indicate the 17 planets orbiting within the EHZ, while gray points depict the remaining planets. Solar system planets are marked with purple circles. The green solid lines correspond to the inner and outer edges of the classical 1D habitable zone, as defined by Kopparapu et al. (2013). The blue dashed line represents the inner edge of the Extended Habitable Zone (EHZ) around M dwarf stars, assuming 30% heat transport efficiency (Wandel 2023a). The brown curve marks the outer edge of the EHZ, determined by the melting of ice sheets driven by geothermal heat (Wandel 2023b). The gray dashed line indicates the tidally locked radius around M dwarf stars. The green shaded region defines the classical HZ and the blue shaded region highlights the extended HZ for tidally locked exoplanets. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Exploring The Habitability And Interior Composition Of Exoplanets Lying Within The Extended Habitable Zone

by Keith CowingJuly 8, 2025July 8, 2025

Studying the habitability, internal structure and composition of exoplanets is crucial for understanding their potential to sustain life beyond our solar system.

Water-equivalent content by weight in the Solar System and model predictions. Left upper panel: Midplane temperature of the disk using T1au = 145, 180, 200 and 300 K (from light blue to dark blue respectively) in Eq. 2. Left lower panel: The solid curves show the snowlines calculated using the Tinacci et al. (2023) BE distribution for the different temperature profiles (colours code as above). The data points show the median values of the water-equivalent content by weight for different objects of the Solar System (Sec. 3), where vertical bars represent the minimum and maximum range. Please note that the values reported in Tab. 1 are considered upper limits (see text). The uncertainty of the formation region of the various objects are shown as ellipses, distinguishing NC, CC, and comet populations. Right: Computed snowlines using T1au = 200 K in Eq. 2 and different models (see text): BE distribution (solid line), single BE (dashed) and condensation at 180 K (dotted). The right and left panels share the same vertical axis. -- astro-ph.EP

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Habitable Zones, Interstellar, Status Report, Water/Hycean Worlds & Oceanography

Was Earth’s Water Acquired Locally During The Earliest Phases Of The Solar System Formation?

by Keith CowingJuly 8, 2025July 8, 2025

The origin of the terrestrial water remains debated, as standard Solar System formation models suggest that Earth formed from dry grains, inside the snowline of the Proto-Solar Nebula (PSN).

Left: The known exoplanet population (divided into two bins of masses above and below 10 Earth masses) as a function of their semi-major axis and of the central stellar mass. The classical habitable zone is shown by the blue area, and the region where star-planet magnetic interactions (SPMI) are expected to occur is shown by the red area, i.e. within the so-called Alfven surface. Right: Modelling of the wind of HD 189733 based on a spectropolarimetric map ( ´ Fares et al. 2017) showing the magnetic connectivity between the hot Jupiter HD 189733 b and its host (from Strugarek et al. 2022). -- astro-ph.IM

Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Imaging & Spectroscopy, Magnetic Fields, Electromagnetism, bioelectricity,, Status Report

Detecting And Characterising The Magnetic Field Of Exoplanets

by Keith CowingJuly 7, 2025July 7, 2025

Magnetic fields play a crucial role in planetary evolution and habitability. While the intrinsic magnetic fields of solar system planets are relatively well understood, the magnetic properties of exoplanets remain […]

A cosmic shoreline dividing exoplanets (errorbars) and Solar System planets (squares) with any type of atmosphere or global surface volatiles (blue symbols, Ai = 1) from those without (brown symbols, Ai = 0). Planets without definitive atmosphere constraints are shown for context (gray symbols, Ai =?). The shoreline defines a plane in the 3D space of (f, vesc, L); each row shows slices that consider a narrow range of stellar luminosity (top), planet escape velocity (middle), and planet flux (bottom). Background colors indicate the modeled probability of an atmosphere at each location (sandy brown for pi = 0, water blue for pi = 1), accounting for the intrinsic width of the shoreline and marginalizing over the parameter uncertainties and the width of the slice; contours (dashed lines) highlight atmosphere probabilities of 5%, 50%, 95% (). -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Status Report

The 3D Cosmic Shoreline For Nurturing Planetary Atmospheres

by Keith CowingJuly 7, 2025July 7, 2025

Various “cosmic shorelines” have been proposed to delineate which planets have atmospheres. The fates of individual planet atmospheres may be set by a complex sea of growth and loss processes, […]

Astrochemistry, Astronomy & Telescopes, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Origin & Evolution of Life, Status Report

Testing Origin-of-Life Theories with the Habitable Worlds Observatory (HWO)

by Keith CowingJuly 3, 2025July 3, 2025

The Habitable Worlds Observatory (HWO) aims to telescopically constrain the frequency and abundance of biospheres in the solar neighborhood.

NASA’s Curiosity rover captured this photo as it ascended the Martian mountain Mt. Sharp. A study proposes a new explanation for why Mars is a barren desert today, despite having many similarities to Earth. Credit Photo by NASA/JPL-Caltech/MSSS

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Desert Worlds, Habitable Zones, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Mars, Press Release

Was Mars Doomed To Be A Desert? Study Proposes A New Explanation

by Keith CowingJuly 2, 2025August 23, 2025

One of the great unsolved problems in modern planetary science is written on the surface of Mars.

Schematic of the post-impact scenario for prebiotic atmospheres (Genda et al. 2017; Zahnle et al. 2020; Wogan et al. 2023). In this scenario, reducing power is delivered to the surface-atmosphere system by reaction of an iron-rich meteor with the planetary ocean, generating a transient Miller-Urey type atmosphere. We anticipate such atmospheres to be strongly distinguishable by HWO observations through their copious concentrations of reducing species (Goodis Gordon et al. 2025). However, we also anticipate such atmospheres to be rare due to their transient nature, and a sample of 25 planets is unlikely to capture them. Figure taken from Wogan et al. (2023). -- astro-ph.IM

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

Prebiosignatures With The Habitable Worlds Observatory (HWO)

by Keith CowingJuly 2, 2025July 2, 2025

The Habitable Worlds Observatory (HWO) aims to characterize habitable exoplanets in search of signs of life. However, detectable life may be rare, either because abiogenesis is intrinsically contingent and unlikely, […]

habitability

The Venus Explorer for Reduced Vapours in the Environment (VERVE)

A Statistical Method For Constraining the Capability of the Habitable Worlds Observatory to Understand Ozone Onset Time in Earth Analogs

Detecting Alien Living Worlds And Photosynthetic Life Using Imaging Polarimetry With The HWO Coronagraph

Exploring The Habitability And Interior Composition Of Exoplanets Lying Within The Extended Habitable Zone

Was Earth’s Water Acquired Locally During The Earliest Phases Of The Solar System Formation?

Detecting And Characterising The Magnetic Field Of Exoplanets

The 3D Cosmic Shoreline For Nurturing Planetary Atmospheres

Testing Origin-of-Life Theories with the Habitable Worlds Observatory (HWO)

Was Mars Doomed To Be A Desert? Study Proposes A New Explanation

Prebiosignatures With The Habitable Worlds Observatory (HWO)

The First Selection Of Optimal Targets For The Lazuli ExtraSolar Coronagraph’s Reflected Starlight Exoplanet Campaign

Paleo-heat Flux Estimates Across Enceladus Derived From Flexural Response Of The Ice Shell

Astrobiologist Dale Andersen’s Antarctic Field Report: 26 October 2026: Flying South

Complex Organic Molecules in Protostars with ALMA Spectral Surveys (COMPASS): I. Overview of the ALMA Large Program

A Technical Reanalysis Of The Viking Carbon Assimilation-Pyrolytic Release Experiment