habitability Archives - Page 22 of 98 - Astrobiology

Schematic of some of the key processes throughout planet formation that influence carbon supply and retention. (a) Key ice/grain sublimation fronts in the disk noted (CO2 between water–CO and that of Silicates at inner disk edge not shown). Planets forming in these locations will receive different compositions at birth (Öberg et al. 2011). Dust that grows beyond the “soot” line (Lodders 2004, Kress et al. 2010, Li et al. 2021) will be rich in refractory carbon content and at greater distances molecular ices. (blow-out:) The drift of carbon-rich pebbles from the outer disk is a key process in carbon supply. Drift itself is influenced by pressure bumps that can lead to a pile-up of pebbles that can be potential sites for planetesimal and planet formation (shown on left side of disk). (b) Solids accrete ice mantles, sublimate key components at sublimation fronts and can collide leading to both growth and fragmentation. (c) Rocky planets and cores of gas-rich planets grow and gain carbon through accretion of pebbles (top) and/or planetesimals (bottom). Impacts of larger planetesimals can also strip atmospheric gas and also supply material. (d) heavy element differentiation can take carbon to the core, and the resulting magma ocean/atmosphere equilibrium can influence atmospheric composition with lighter gases escaping depending on the planet mass. Figure credit to N. Fuller and Sayo Studio. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gas Giants, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Press Release

Carbon From Interstellar Clouds To Habitable Worlds

by Keith CowingFebruary 12, 2026February 12, 2026

Carbon is an essential element for a habitable world. Inner (r < 3 au) disk planetary carbon compositions are strongly influenced by supply and survival of carbonaceous solids. Here we […]

The observed sources and data collected during the K2-18b observing campaign. (Left) The dates of the observations and the frequencies in which signals were detected. (Right) The location of the 64 coherent beams (gray circles), the position of K2-18 (red star), and the FWHM PB for the MeerKAT telescope at L-band. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Intelligence & Language, SETI & Technosignatures, Status Report, Water/Hycean Worlds & Oceanography

A Narrowband Technosignature Search Toward The Hycean Candidate K2-18b Using The VLA And MeerKAT

by Keith CowingFebruary 11, 2026February 11, 2026

K2-18b, a sub-Neptune exoplanet located in the habitable zone of its host star, has emerged as an important target for atmospheric characterization and assessments of potential habitability.

Different Flavors of Planets -- Grok via Astrobiology.com

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Press Release

Why Only A Small Number Of Planets Are Suitable For Life

by Keith CowingFebruary 10, 2026February 10, 2026

For life to develop on a planet, certain chemical elements are needed in sufficient quantities. Phosphorus and nitrogen are essential. Phosphorus is vital for the formation of DNA and RNA, […]

Ventilation of the ocean interior improves with slowing rotation.-- Science via PubMed

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Gaia - Planetary Perspectives, Habitable Zones, Status Report, Water/Hycean Worlds & Oceanography

Slowing Planetary Rotation Influences Ocean Nutrient Cycling And Oxygenation

by Keith CowingFebruary 7, 2026

Marine habitability for complex life on Earth and Earth-like planets requires bioavailable nutrients and dissolved oxygen. The cycling of nutrients and oxygen is controlled by physical ocean circulation.

Artist’s impression of Earth around 700 million years ago during Snowball Earth Credit This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license. Attribution must be given to Pablo Carlos Budassi.

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Extinction events, Gaia - Planetary Perspectives, Habitable Zones, Icy Worlds, Press Release, Water/Hycean Worlds & Oceanography

Ancient Rocks Reveal Annual Climate Cycles During Snowball Earth

by Keith CowingFebruary 6, 2026February 6, 2026

Scientists at the University of Southampton have uncovered evidence from ancient rocks that the Earth’s climate continued to fluctuate during its most extreme ice age – known as Snowball Earth.

The distribution of currently known exoplanets from the NASA Exoplanet Archive that are in the VZ and have radii Rp ≲ 2 R⊕. The inner VZ boundary is indicated by the red line on the left, and the outer VZ boundary is shown on the right. As of November 2025 there are 370 potential exoVenuses, and this number will continue to grow as there are over 7000 TESS planet candidates yet to be confirmed. The VZ will be calculated and translated against the IWA for all proposed HWO priority targets. -- astro-ph.EP

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

Imaging Venus-like Worlds: Spectral, Polarimetric, And UV Diagnostics For The Habitable Worlds Observatory

by Keith CowingFebruary 5, 2026February 5, 2026

Understanding planetary habitability requires a comparative approach that explores the divergent evolutionary outcomes of Earth and Venus.

Quantitative morphological metric extraction results and numerical simulation results. A. Spatial distribution of DAF across the study area, overlaid on a shaded relief base map derived from DTEEC_033165_2195_032875_2195_A01 (26). Colors represent specific DAF values indicated by the color bar on the bottom right. The MBT boundary is shown as a black dashed line. B. Schematic diagram defining the key morphological feature of MBT. The curve represents the terrain tangent of MBT. The yellow shaded areas indicate depression. The dashed line represents the depression threshold elevation (DTE) (see SI Appendix). C-E. HiRISE images of three local MBT in the study area. All three images share the same scale-bar. F-H. Detrended observed elevation data for three MBT areas shown in C-E, respectively (SI Appendix, Fig. S3). The white contour lines, which correspond to DTE values, outline the depression areas. Colors indicate elevation value using a color bar shown to the right of H. The I-K. Simulation results with increasing maximum stone movement rate (𝑣max): 3.25 mm/cycle (I), 3.40 mm/cycle (J) and 3.90 mm/cycle(K).Colors represent the simulated elevation using a common color bar shown to the right of K. -- astro-ph.EP

Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Caves, Craters, Mountains, Subsurface, Lava Tubes, Desert Worlds, Fossils & Paleontology, Habitable Zones, Mapping, Geodesy, Cartography, Bathymetry, Mars, Status Report, Water/Hycean Worlds & Oceanography

Sculpting Of Martian Brain Terrain Reveals The Drying Of Ancient Mars

by Keith CowingFebruary 5, 2026February 5, 2026

The Martian brain terrain (MBT), characterized by its unique brain-like morphology, is a potential geological archive for finding hints of paleoclimatic conditions during its formation period.

Mars dust storm captured by ESA’s Mars Express near the north polar ice cap. Credits: ESA/DLR/FU Berlin (larger image)

Astrogeology, Atmospheres, Climate, Weather, Desert Worlds, Habitable Zones, Mars, Press Release, Water/Hycean Worlds & Oceanography

An Unusual Dust Storm Reveals How Mars Lost Some Of Its Water

by Keith CowingFebruary 3, 2026

The current image of Mars as an arid and hostile desert contrasts with the history revealed by its surface. Channels, minerals altered by water, and other geological traces indicate that […]

A schematic of the key processes included in our abiotic Earth model. Remotely observable quantities (surface temperature, albedo, and atmospheric H2O and CO2) are in bold. Volatile cycling is diagrammed in more detail in Figure 2. -- astro-ph.EP

Analog Studies, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Origin & Evolution of Life, Status Report, Water/Hycean Worlds & Oceanography

A Whole-planet Model Of The Earth Without Life For Terrestrial Exoplanet Studies

by Keith CowingFebruary 3, 2026February 3, 2026

As the only known habitable (and inhabited) planet in the universe, Earth informs our search for life elsewhere. Future telescopes like the Habitable Worlds Observatory (HWO) will soon look for […]

Comparison of the posteriors (solid lines) from our four different fiducial models, labeled inset. The dashed-lines represent the likelihood functions of each, and the solid grey line is the prior - which is identical to the fourth model of indifference and thus not explicitly shown. -- astro-ph.EP

Exoplanets, -moons, -comets, Habitable Zones, Mapping, Geodesy, Cartography, Bathymetry, Origin & Evolution of Life, Status Report, Water/Hycean Worlds & Oceanography

What To Make Of The Earth’s Curiously Intermediate Land Fraction?

by Keith CowingFebruary 3, 2026February 3, 2026

Approximately two-thirds of the Earth, the only known inhabited planet, is covered in ocean. Why not 0.01% or 99.99%? It has been previously suggested that this may represent a certain […]