astrogeology Archives - Page 94 of 105 - Astrobiology

This view of the icy surface of Jupiter's moon, Europa, is a mosaic of two pictures taken by the Solid State Imaging system on board the Galileo spacecraft during a close flyby of Europa on Feb. 20, 1997. The pictures were taken from a distance of 1,240 miles (2,000 kilometers ). The area shown is about 8.7 miles by 10.6 miles (14 kilometers by 17 kilometers), and has a resolution of 22 yards (20 meters) per pixel. Illumination is from the right (east). The picture is centered at about 14.8 north latitude, 273.8 west longitude, in Europa's trailing hemisphere. Larger image

Astrogeology, Europa, Icy Worlds, Status Report

Europa’s Double Ridges Produced By Ice Wedging

by Keith CowingFebruary 29, 2024February 29, 2024

Double ridges are sprawling features observed globally across the icy surface of Europa. They consist of two topographic highs flanking a trough.

Mean abundance measurements of our sample with standard errors of the means (standard deviation divided by square root of number of stars) as a function of condensation temperature compared to the Sun. Top: All test set solar analogs as navy filled circles and identified planet hosts as orange hexagons. The Sun appears relatively refractory depleted with increasing condensation temperature compared to these samples replicating Bedell et al. (2018), and the solar analogs and planet hosts are chemically indistinguishable within 2-3σ. Bottom: All test set solar analogs as navy filled circles, close-in giant planet hosts as purple unfilled circles, giant planet hosts as pink unfilled diamonds, and terrestrial/small planet hosts as green unfilled squares. The Sun still appears relatively depleted compared to these four samples, which are still chemically indistinguishable within 2-3σ. -- astro-ph.SR

Astrogeology, Astronomy & Telescopes, Exoplanets, -moons, -comets, Gaia Mission, Space Weather & Heliophysics, Status Report, Stellar Cartography

The Sun Remains Relatively Refractory Depleted: Elemental Abundances for 17,412 Gaia RVS Solar Analogs and 50 Planet Hosts

by Keith CowingFebruary 28, 2024November 16, 2024

The elemental abundances of stars, particularly the refractory elements (e.g., Fe, Si, Mg), play an important role in connecting stars to their planets.

The plots of stellar metallicity ([Fe/H]) versus planetary orbital period for all transiting planets from the NASA exoplanet archive. Tranet stands for transiting planet. The transiting planets are split into four groups based on the multiplicity of their systems and are placed on four different panels. The two dotted vertical lines split the metallicity range into three metallicity regions, namely, sub-solar, solar, and super-solar. While low-multiplicity systems are evenly distributed across hosts of all metallicities there is a paucity of high-multiplicity systems around hosts of high metallicity indicating the effect of cold Jupiters on the inner planet multiplicity. -- astro-ph.EP

Exoplanets, -moons, -comets, Gas Giants, Habitable Zones, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

Constraining Planetary Formation Models Using Conditional Occurrences of Various Planet Types

by Keith CowingFebruary 28, 2024February 28, 2024

We report the conditional occurrences between three planetary types: super-Earths (m sin i < 10 M⊕, P < 100 days), warm Jupiters (m sin i > 95 M⊕, 10 < […]

Chinguetti meteorite fragment -- Wikipedia

Astrogeology, Away Teams & Field Reports, Caves, Craters, Mountains, Subsurface, Lava Tubes, Impact events, Meteorites & Asteroids, Press Release

Away Team Idea: New Evidence On The Lost Giant Chinguetti Meteorite

by Keith CowingFebruary 23, 2024February 23, 2024

The giant Chinguetti meteorite that Gaston Ripert reported seeing in 1916 has never been found. A radionuclide analysis by Welten et al (2001) of the 4.5kg mesosiderite that Ripert recovered, […]

Interstellar comet 2I/Borisov -- Wikipedia

Astrochemistry, Astrogeology, Astronomy & Telescopes, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Interstellar, Status Report

Pre-perihelion Monitoring of Interstellar Comet 2I/Borisov

by Keith CowingFebruary 21, 2024July 12, 2025

The discovery of interstellar comet 2I/Borisov offered the unique opportunity to obtain a detailed analysis of an object coming from another planetary system, and leaving behind material in our interplanetary […]

Transmission spectra of pure H2O ice (1) and H2O ice mixed with silicate grains at 10K (2) at 200 K, above the desorption temperature of H2O ice. -- astro-ph.GA

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Imaging & Spectroscopy, Status Report

Trapped Water On Silicates In The Laboratory And In Astrophysical Environments

by Keith CowingFebruary 21, 2024February 21, 2024

Existence of strongly bound water molecules on silicate surfaces, above the desorption temperature of water ice, has been first predicted by computational studies and recently demonstrated by laboratory experiments.

A schematic chronology of the early asteroid belt based on the evidence discussed in the text. CAI formation defines t = 0 and primary planetesimals are assumed to form quickly. Within a few hundred thousand years most of the mass is in the form of large planetesimals, which become dominated by magma interiors, as shown by the red line labeled magma fraction. The energy source is 26Al, whose level declines with a half-life of 0.717 Ma from an assumed initial value of 4 at t = 0, where a level of 1 corresponds to the amount of energy (1.6 kJ/g) needed to just reach the liquidus of a perfectly insulated cold primitive starting material. Chondrules formed between ∼1-4 Ma when exposed to hot magma released during a collision, as illustrated by the drawing in the right hand panel by David A. Harvey (astroart.com) originally depicting the formation of a ring around the Earth. Chondrule formation ends when the LDPs have cooled sufficiently that magma does not reach their surfaces even during collisions. Jupiter may form at around 3-4 Ma and begin clearing the asteroid belt of many of its larger objects. -- astro-ph.EP

Astrochemistry, Astrogeology, Comets and Asteroids, Meteorites & Asteroids, Status Report

Chondrule Formation During Low-Speed Collisions of Planetesimals: A Hybrid Splash-Flyby Framework

by Keith CowingFebruary 21, 2024February 21, 2024

Chondrules probably formed during a small window of time ∼1-4 Ma after CAIs, when most solid matter in the asteroid belt was already in the form of km-sized planetesimals.

Artist’s concept of a collision between two objects in the distant Kuiper Belt. Such collisions are a major source of dust in the belt, along with particles kicked up from Kuiper Belt objects being peppered by microscopic dust impactors from outside of the solar system. Credit: Dan Durda, FIAAA

Astrochemistry, Astrogeology, Astronomy & Telescopes, Icy Worlds, Imaging & Spectroscopy, Pluto, Press Release

Astrogeology/Astrochemistry/Astrobiology Update: New Horizons Detects Dusty Hints Of An Extended Kuiper Belt

by Keith CowingFebruary 20, 2024February 20, 2024

New observations from NASA’s New Horizons spacecraft hint that the Kuiper Belt – the vast, distant outer zone of our solar system populated by hundreds of thousands of icy, rocky […]

Jared Ralleta and Alice Baldridge at work in Kilbourne Hole, Potrillo Volcanic Field. -- NASA Note: Jared is using a Malvern Panalytical ASD FieldSpec 4 Hi-Res: High Resolution Spectroradiometer with a contact probe.

Astrogeology, Away Teams & Field Reports, Caves, Craters, Mountains, Subsurface, Lava Tubes, Exploration Gear & Tech, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Status Report, Tricorders & Sensors

NASA Goddard Geochemistry Group Away Team Practices Tricorder Use On Volcanic Deposits

by Keith CowingFebruary 20, 2024February 20, 2024

Location: Kilbourne Hole, Potrillo Volcanic Field, New Mexico

Makemake -- NASA

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Comets and Asteroids, Habitable Zones, Icy Worlds, Mapping, Geodesy, Cartography, Bathymetry, Pluto, Status Report, Water/Hycean Worlds & Oceanography

Moderate D/H Ratios in Methane Ice on Eris and Makemake as Evidence of Hydrothermal or Metamorphic Processes in Their Interiors: Geochemical Analysis

by Keith CowingFebruary 19, 2024February 20, 2024

Dwarf planets Eris and Makemake have surfaces bearing methane ice of unknown origin. D/H ratios were recently determined from James Webb Space Telescope (JWST) observations of Eris and Makemake, giving […]