The Planetary Science Journal Archives - Astrobiology

Example Uranus orbit insertion outside the zeta ring. Uranus orbit insertion maneuver traverses Uranus’s ring plane in the epsilon-ν ring gap (left). Uranus orbit insertion (UOI) burn (1.62 hr duration, 1331 m s−1) as viewed from Earth (right). While this example occurs in full view of ground stations, this is not a feature of all UOI geometries, where some portion of the burn is typically occulted with respect to Earth. Uranus’s orbital velocity vector is indicated for reference. Reproduced from D. Ellison et al. (2025).

Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Ice Giant, Imaging & Spectroscopy, Missions & Hardware, Status Report, Uranus

Uranus Orbiter and Probe: Mission Challenges and Concept Updates Since the Origins, Worlds, and Life Decadal Survey

by Keith CowingJune 14, 2026June 14, 2026

Origins, Worlds, and Life: Planetary Science and Astrobiology in the Next Decade identified a Uranus Orbiter and Probe as the highest-priority strategic mission for the decade 2023–2032, as it enables […]

Locations (yellow circles) of ROIs that include paterae, potential flows, and cryovolcanic candidate regions (K. Stephan et al. 2021a) on top of the global geological map of Ganymede from G. C. Collins et al. (2013). Mercator projection. -- The Planetary Science Journal

Astrogeology, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Ganymede, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Missions & Hardware, Status Report

Potential Cryovolcanic Regions on Ganymede: A Priority Target for JUICE

by Keith CowingJune 7, 2026June 26, 2026

One of the Jupiter Icy Moons Explorer (JUICE) mission goals of the European Space Agency, launched in 2023 April, is the detailed characterization of Ganymede, Jupiter’s largest moon and a […]

Artist’s impression of Dragonfly landing on Titan. Image: NASA/Johns Hopkins APL/Steve Gribben

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Missions & Hardware, Robotics/Rovers/UAVs, Status Report, Titan, Water/Hycean Worlds & Oceanography

Science Goals and Objectives for the Dragonfly Titan Rotorcraft Relocatable Lander

by Keith CowingApril 28, 2026April 28, 2026

NASA’s Dragonfly mission will send a rotorcraft lander to the surface of Titan in the mid-2030s. Dragonfly’s science themes include investigation of Titan’s prebiotic chemistry, habitability, and potential chemical biosignatures […]

Schematic of the procedure in two sets of experiments performed with carbonated water. The Planetary Science Journal

Analog Studies, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Europa, Exoplanets, -moons, -comets, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Status Report, Water/Hycean Worlds & Oceanography

The Fate of Frozen Carbonated Water at Europa-like Conditions

by Keith CowingMarch 20, 2026

We present the results of experiments probing the retention of CO2 in crystalline water ice, frozen sodium chloride (NaCl) brines, and flash-frozen carbonated water using diffuse reflectance infrared spectroscopy.

Strength of key long-term feedbacks governing Earth’s climate system (D. S. Abbot 2016; D. D. B. Koll & T. W. Cronin 2018; C. W. Arnscheidt & D. H. Rothman 2020; P. Forster et al. 2021). Each bar represents the feedback parameter in W m−2 K−1, estimated from Earth system model assessments and paleoclimate constraints. The upper axis shows the approximate feedback strength associated with a 50 K climate perturbation, representative of transitions between major states (e.g., snowball to temperate). Feedbacks are sorted by magnitude. Negative values (blue) represent stabilizing feedback that dampens temperature changes, while positive values (orange) indicate destabilizing feedback that amplifies them. Outgoing longwave radiation and the carbonate–silicate cycle are among the strongest stabilizing processes, while the ice–albedo feedback exerts a strong destabilizing influence. Models incorporating the three dominant types of feedback explain the general behavior of Earth’s long-term mean climate. -- The Planetary Science Journal

Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Habitable Zones, Status Report

Not Earth-like Yet Temperate? More Generic Climate Feedback Configurations Still Allow Temperate Climates in Habitable Zone Exo-Earth Candidates

by Keith CowingMarch 20, 2026March 20, 2026

Earth’s climate is influenced by over a dozen types of feedback, but only three dominate its long-term climate behavior. Models of the exoplanet habitable zone (HZ) assume that this is […]

Spectra of NEOs with (potential) 3 μm absorption features. (A) Spectrum of (161989) Cacus as observed on 2022 September 3 and 4. (B) (756998) 2024 CR9 as observed on 2024 June 9. (C) 1998 HH 49 as observed on 2023 October 19. (D) 2006 WB as observed on 2024 November 27. The blue points represent the reflectance spectra (thermal component removed) and the red dashed lines are the reflected continua. -- The Planetary Science Journal via X-mol.net

Astrochemistry, Astrogeology, Biosignatures & Paleobiology, Comets and Asteroids, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Meteorites & Asteroids, Space Weather & Heliophysics, Status Report

Hydration Features on Near-Earth Objects: Integrating New Data with Prior Results

by Keith CowingMarch 10, 2026March 10, 2026

Near-Earth objects (NEOs) are excellent laboratories for testing processes that affect airless bodies, as well as informing us about solar system history.

Contour plots of surface temperature, cloud water column, albedo, and OLR for our four representative climate states. -- Planetary Science Journal

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report, TRAPPIST-1

Chemistry, Climate, And Transmission Spectra Of TRAPPIST-1 e Explored With A Multimodel Sparse Sampled Ensemble

by Keith CowingOctober 16, 2025October 16, 2025

TRAPPIST-1 e is one of a few habitable zone exoplanets that is amenable to characterization in the near term. In this study our motivations are both scientific and technical.

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.