The Planetary Science Journal Archives - Page 2 of 3 - Astrobiology

Orientation of the tidal bulge. Panel (a) displays the bulge of the ice shell under the action of the static tide, and the other panels display the bulge under the action of the total tide, depending on whether the shell is hard (panel (b)) or soft (panel (c)). For given values of γS and γice (angles of Saturn in its epicycle and of the shell, respectively), the resulting orientation of the bulge (γbul) depends on the shell’s hardness. When it is hard, the shell hardly changes its shape relative to γice. When it is soft, the bulge nearly points at Saturn, whatever the value of γice. The hardness parameter is defined in Equation (27). -- The Planetary Science Journal

Astrogeology, Enceladus, Europa, Habitable Zones, Icy Worlds, Mapping, Geodesy, Cartography, Bathymetry, Status Report, Titan, Water/Hycean Worlds & Oceanography

Enceladus’ Tidal Heating: A Simple Approach

by Keith CowingOctober 11, 2025October 11, 2025

Saturn’s moon Enceladus has a global ocean that is covered by an ice shell. The moon’s eccentric orbit forces the shell to librate, which distorts the shell and thereby generates […]

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Europa, Habitable Zones, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

Parameter Space Exploration of Low-to-moderate-temperature Hydrothermal Systems on Ocean Worlds Using a Monte Carlo Framework

by Keith CowingSeptember 5, 2025September 5, 2025

We explore the hydrogeologic and physical conditions necessary to sustain hydrothermal activity within the shallow subseafloors of ocean worlds, exploring wide ranges of multiple parameters using a Monte Carlo framework.

Drill (a) and scoop (b) UAS sampling systems. -- The Planetary Science Journal

Analog Studies, Astrogeology, Exploration Gear & Tech, Mapping, Geodesy, Cartography, Bathymetry, Mars, Missions & Hardware, Polar / Alpine Expeditions, Robotics/Rovers/UAVs, Sample Return, Status Report

Unoccupied Aircraft Systems Sampling For Earth And Mars

by Keith CowingAugust 19, 2025August 19, 2025

Unoccupied aircraft systems (UAS) technology on Earth has become increasingly prevalent and accessible, and for extraterrestrial applications, the Ingenuity helicopter has proven the viability of flight on Mars.

Impact velocities and first contact pressures relevant to OW for ice (solid, black) and basalt (dashed, gray) projectiles into ice targets at a representative span of impact angles between 15° and 75°. Shock studies of biota (green) or biologically relevant molecules (black) shown along the y-axes; impactors in the inner solar system shown at the top for context. Vertical orange, teal, and magenta bars indicate the average impact velocity of heliocentric impactors calculated by Zahnle et al. (2008); Nesvorný et al. (2023)a; Martins et al. (2013)b; Goldman et al. (2010)c; Blank et al. (2001)d; Furukawa et al. (2015)e; Horneck et al. (2001); Burchell (2007); Stöffler et al. (2007); Burchell et al. (2014)f; Traspas & Burchell 2021 g; O’Brien & Sykes (2011)h; Le Feuvre & Wieczorek (2008). -- Planetary Science Journal

Enceladus, Europa, Extinction events, Habitable Zones, Icy Worlds, Impact events, Mapping, Geodesy, Cartography, Bathymetry, Meteorites & Asteroids, Press Release, Titan, Water/Hycean Worlds & Oceanography

Impacts on Ocean Worlds Are Sufficiently Frequent and Energetic to Be of Astrobiological Importance

by Keith CowingAugust 12, 2025

Evidence for the beneficial role of impacts in the creation of urable or habitable environments on Earth prompts the question of whether meteorite impacts could play a similar role at […]

Visual summary of key considerations and arguments about the nature and scope of the definition and use of the term “habitable.” There are strong and valid arguments both for a simpler and more specific meaning and for a more complex and more universal meaning. Any single definition for “habitability” fails to meet the majority of the requirements. -- The Planetary Science Journal

Astrobiology (general), Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Courses, Habitable Zones, Nomenclature, Systematics, Natural History, Planetary Protection & Biosafety, Science Fiction, SETI & Technosignatures, Status Report

A Terminology And Quantitative Framework For Assessing The Habitability Of Solar System And Extraterrestrial Worlds

by Keith CowingJuly 17, 2025July 17, 2025

The search for extraterrestrial life in the solar system and beyond is a key science driver in astrobiology, planetary science, and astrophysics.

The conceptual scheme outlines the primary prerequisites for habitability in ocean worlds, highlighting the importance of water, energy, CHNOPS, and TMs. The horizontal bar on the bottom denotes our assessment of the extent of exploration of each subject area indicated in the top bar. Ocean worlds are not to scale. The Europa image is modified from the NASA Photojournal PIA01295, credit NASA/JPL/University of Arizona. The Titan image is modified from the NASA Photojournal PIA20016, credit NASA/JPL/University of Arizona/University of Idaho. The Callisto image is modified from the NASA Photojournal PIA03456, credit NASA/JPL/German Aerospace Center (DLR). The Enceladus image is modified from the NASA Photojournal PIA06187, credit NASA/JPL/Space Science Institute. The Ganymede image is modified from the NASA Photojournal PIA01972, credit NASA/JPL. The Pluto image is modified from the NASA Photojournal PIA11709, credit NASA/Johns Hopkins University Applied Physics Laboratory/Southwest Research Institute. The Triton image is modified from the NASA Photojournal PIA01994, credit NASA/JPL. -- The Planetary Science Journal

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

Plume Particle Ejecta Can Trace Habitat-forming Gradients in Ocean Worlds: Insights from Planet Earth Geochemistry

by Keith CowingMay 8, 2025May 8, 2025

Upcoming explorations for habitability in the ocean worlds of the solar system can greatly benefit from searching beyond parameters such as water, organics, nitrogen, phosphate, and silicate and being able […]

This final prospectivity map synthesizes eight evidence layers: ISRs, maximum temperature, PSRs, slope, curvature, aspect, distance to PSRs, and density of PSRs. The color gradient signifies prospectivity levels, with cool tones indicating higher potential and warm tones suggesting lower potential. Specifically, dark blue areas are deemed highly prospective, light blue suggests favorable conditions, yellow denotes permissive regions, and red areas are considered nonprospective. -- The Planetary Science Journal

Artemis & Lunar Exploration, Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exploration Gear & Tech, Icy Worlds, Missions & Hardware, Moon, Robotics/Rovers/UAVs, Status Report, Water/Hycean Worlds & Oceanography

Astrochemistry: Prospectivity Modeling of the NASA VIPER Landing Site at Mons Mouton near the Lunar South Pole

by Keith CowingMay 7, 2025May 7, 2025

We use a high-resolution digital elevation model and a numerical thermal model to produce a variety of inputs for a water-ice prospectivity model for the Volatiles Investigating Polar Exploration Rover […]

Model of the observed distribution of CO2 based on our results shown in Figure 4. The resolution and the subobserver point are aligned with the JWST's observation (2.7°N, 93°W; S. K. Trumbo & M. E. Brown 2023; G. Villanueva et al. 2023). Additionally, the cross section from the observer's perspective is considered. As a result, the intensity around the north pole seems stronger than around the south pole (a). The regions surrounded by white lines are Tara Regio (∼10°S, 75°W) and Powys Regio (∼0°S, 150°W) (E. J. Leonard et al. 2024). -- The Planetary Science Journal

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Cryobiology, Europa, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Equatorial CO2 Distribution Suggests Active CO2 Supply on Europa

by Keith CowingMay 7, 2025

The James Webb Space Telescope’s (JWST) observation of Europa recently revealed CO2 accumulation around geologically young chaos terrains Tara Regio and Powys Regio.

The DSMC simulation results of Europa's gas plumes with four case studies. Top: number density distribution (shown in contours with a color scale in units of # m−3). Middle: gas velocity distribution (shown in contours with a color scale in units of m s−1). Gas flow streamlines are presented too. Bottom: column density distribution (shown in contours with a color scale in units of # m−2). Both axes are arbitrary and presented in units of Europa radius. -- The Planetary Science Journal

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Europa, Icy Worlds, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Surface Deposition Of Icy Dust Entrained In Europa’s Plumes

by Keith CowingApril 21, 2025April 21, 2025

Europa, an icy moon of Jupiter, features complex surface characteristics shaped by tidal forces and interactions with its subsurface ocean, making it a key target for astrobiology research.

Dramatic plumes, both large and small, spray water ice and vapor from many locations along the famed "tiger stripes" near the south pole of Saturn's moon Enceladus. The tiger stripes are four prominent, approximately 84-mile- (135-kilometer-) long fractures that cross the moon's south polar terrain. Larger image

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Ceres, Enceladus, Europa, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

Supercooling, Glass Formation, and Mineral Assemblages upon Freezing of Salty Ice Grains from Enceladus’s Ocean

by Keith CowingApril 21, 2025April 21, 2025

The analysis of micrometer-sized ice grains emitted into space by Saturn’s moon Enceladus suggests that the moon’s subsurface ocean may be habitable. However, the formation conditions of these ice grains […]