habitability Archives - Page 75 of 98 - Astrobiology

Mixing ratios for the major species in the Archean Earth-like (ARE) atmospheres and temperature profiles. Each line represents a self-consistent Earth-like atmosphere orbiting a stellar host. Earlier-type M dwarf hosts are lighter and later-type M dwarf hosts are darker. The dashed blue line represents profiles for the Earth orbiting the Sun for comparison. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy

There’s More To Life Than O2: Simulating the Detectability Of A Range Of Molecules For Ground-based high-resolution Spectroscopy Of Transiting Terrestrial Exoplanets

by Keith CowingApril 24, 2023April 27, 2023

Within the next decade, atmospheric O2 on Earth-like M dwarf planets may be accessible with visible–near-infrared, high spectral resolution extremely large ground-based telescope (ELT) instruments.

Top panel: example wavelength sector showing the model contribution from CO only. The model is shown at simulated resolution (grey, sampled every ˚Angstrom) and after being convolved with the observed point spread function and rebinned onto the detector’s wavelength grid (black). Middle panel: visualisation of our method for detecting CO sub-band structure. Red and blue portions indicate wavelengths that are in-band or out-of-band, respectively. Note these wavelength selections are refined in Figure 4. Bottom panel: model contributions per molecule, where H2O is the only significant molecular absorber in this wavelength sector other than CO. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets

Detection of Carbon Monoxide’s 4.6 Micron Fundamental Band Structure In WASP-39b’s Atmosphere With JWST NIRSpec G395H

by Keith CowingApril 24, 2023April 27, 2023

Carbon monoxide (CO) is predicted to be the dominant carbon-bearing molecule in giant planet atmospheres, and, along with water, is important for discerning the oxygen and therefore carbon-to-oxygen ratio of […]

An exploded star can pose more risks to nearby planets

Astronomy & Telescopes, Exoplanets, -moons, -comets, Extinction events, Habitable Zones, Space Weather & Heliophysics

New Stellar Danger to Exoplanets Identified by Chandra X-ray Observatory

by Keith CowingApril 21, 2023April 27, 2023

An exploded star can pose more risks to nearby planets than previously thought, according to a new study from NASA’s Chandra X-ray Observatory and other X-ray telescopes. This newly identified […]

Poynting flux divergence in (a) the bow shock nose and (b) magnetopause reconnection regions. Simulation with southward IMF orientation, |B|IMF = 30 nT and Pd = 1.2 nPa. Black lines indicate the region of the bow shock (n > 20 cm−3 ), the red lines the exoplanet magnetic field lines and the pink iso-surface the reconnection region in the XZ plane (|B| < 5 nT). -- -astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biophysics, Exoplanets, -moons, -comets, Habitable Zones, Radiation, Space Weather & Heliophysics, Water/Hycean Worlds & Oceanography

MHD Study Of Extreme Space Weather Conditions For Exoplanets With Earth-like Magnetospheres: On Habitability Conditions And Radio-emission

by Keith CowingApril 18, 2023April 27, 2023

The present study aims at characterizing the habitability conditions of exoplanets with an Earth-like magnetosphere inside the habitable zone of M stars and F stars like tau Boo, caused by […]

During the depths of a planetwide ice age, pockets of open ocean might have existed outside the tropics. HUYUE SONG

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Habitable Zones, Icy Worlds, Press Release

Snowball Earth Might Have Been Slushball Earth

by Keith CowingApril 8, 2023April 8, 2023

At least five ice ages have befallen Earth, including one 635 million years ago that created glaciers from pole to pole.

Rochester researchers Wriju Chowdhury and Dustin Trail reveal information about early Earth using tiny zircon crystals, which are billions of years old and a fraction of a millimeter in size (scale bars are in micrometers, where 1 micrometer = 0.000001 meter). The researchers use an imaging technique called cathodoluminescence that fires electrons from a cathode at a sample. The holes in the crystals are from a laser that removed part of the grain to allow the researchers to acquire chemical information. (Smithsonian Institution photo)

Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Habitable Zones, Press Release

Was Plate Tectonics Occurring When Life First Formed On Earth?

by Keith CowingApril 4, 2023April 4, 2023

Earth is a dynamic and constantly changing planet. From the formation of mountains and oceans to the eruption of volcanoes, the surface of our planet is in a constant state […]

Example two-dimensional projections of the initial positions and orbits of each object in our four-body simulations (including planet e). Panel (a) shows the top-down and edge-on projections of 20 random realizations of the system, with the initial orbits (lines) and positions (points) of planet e shown in orange, and the initial orbits and positions of planet f shown in blue. The black “?” shows the position of the host star, and the dashed black line shows the fixed orbital semi-major axis for planet d. The red boxes indicate the limits of the area plotted in panel (b), which shows a zoomed-in version of the system highlighting the initial position and orbit of the satellite, “s,” (red) orbiting planet f. The 20 system realizations shown here represent the initial conditions at a single grid cell in Figure 3, used to determine the fractional stability for a given Pe and ee. -- astro-ph.EP

Astronomy & Telescopes, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report

Stability and Detectability of Exomoons Orbiting HIP 41378 f, a Temperate Jovian Planet with an Anomalously Low Apparent Density

by Keith CowingMarch 27, 2023March 27, 2023

Moons orbiting exoplanets (“exomoons”) may hold clues about planet formation, migration, and habitability. We investigate the plausibility of exomoons orbiting the temperate (Teq=294 K) giant (R=9.2 R⊕) planet HIP 41378 […]

Two proposed mechanisms for H2O2 generation at quartz–water interfaces. (A) Stress-induced cleavage of Si–O bonds. Applied force is represented by a linear falling potential (dashed line), which is added to the Morse potential of the unstretched Si–O bond (dotted line), thus resulting in a force-deformed Morse potential (solid line). The new dissociation energy D′ is smaller than D in the case of a stretching force. Modified after Kauzmann et al. (42). The probability of generation of surface-bound radicals in quartz therefore increases during mechanical processes. (B) Contact of water on freshly fractured surface of abraded quartz. Modified after Schoonen et al. (32). (C) Generation of H2O2 and O2 in the reaction between H2O and oxygen radical (≡SiO•). (D) Generation of rocky H2O2 and O2 in the reaction between H2O and peroxy radical (≡SiOO•). Surface-bound radicals are formed through homolysis of Si–O bonds, including ≡SiO•, ≡SiOO•, and E′ center (≡Si•), while surface charges (≡Si+ and ≡SiO–) for heterolysis. Silanol groups (≡SiOH) are end products on quartz surface after hydroxylation. -- Guangzhou Institute

Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Habitable Zones, Origin & Evolution of Life, Press Release

A Novel Origin Of Abiotic Oxidants On Early Earth: Minerals

by Keith CowingMarch 23, 2023March 23, 2023

Molecular oxygen (O2) is essential for respiration on today’s Earth, but the early atmosphere was almost devoid of oxygen until the Great Oxidation Event. How then did Earth’s atmosphere become […]

Image depicts divergent evolutionary pathways of Earth and Venus after formation. CREDIT O’Rourke, J.G., Wilson, C.F., Borrelli, M.E. et al.

Astronomy & Telescopes, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Habitable Zones, Press Release, Venus

Hunting For Venus 2.0

by Keith CowingMarch 22, 2023March 22, 2023

With the first paper compiling all known information about planets like Venus beyond our solar system, scientists are the closest they’ve ever been to finding an analog of Earth’s “twin.”

Artist's view of a liquid water exomond created by the authors using Midjourney.

Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Press Release, Water/Hycean Worlds & Oceanography

Habitable Moons Orbiting Free-Flying Planets

by Keith CowingMarch 21, 2023March 21, 2023

Liquid water is one of the most important conditions for the emergence of life as we know it on earth. Researchers from the ORIGINS cluster from the fields of astrophysics, […]