tides Archives - Astrobiology

imaginary parts of tidal Love numbers,

Astrogeology, Exoplanets, -moons, -comets, Mapping, Geodesy, Cartography, Bathymetry, Press Release, Water/Hycean Worlds & Oceanography

Tidally Driven Inertial Waves Enhance Eccentricity Damping And Spin Evolution In Planets And Stars

by Keith CowingNovember 6, 2025

Tidal interactions influence the orbital motions of binary star systems and extrasolar planets alike.

Deep Space Climate Observatory (DSCOVR) satellite's EPIC maintains a constant view of the fully illuminated Earth as it rotates, providing scientific observations of ozone, vegetation, cloud height and aerosols in the atmosphere. About twice a year the camera captures the Moon and Earth together as the orbit of DSCOVR crosses the orbital plane of the Moon. These images were taken between 3:50 p.m. and 8:45 p.m. EDT showing the moon moving over the Pacific Ocean near North America. The North Pole is in the upper left corner of the image. It is in the original orientation as taken by the spacecraft. larger image

Exoplanets, -moons, -comets, Moon, Press Release

Initial Conditions For Tidal Synchronisation Of A Planet By Its Moon

by Keith CowingSeptember 16, 2025September 16, 2025

Moons tidally interact with their host planets and stars. A close moon is quickly synchronised by the planet, or becomes captured in a higher spin-orbit resonance.

The HHZ (blue shaded regions) and dark HHZ (red shaded regions) around a 0.12M⊙ star for a 7M⊕, 1.7R⊕ hycean planet with tidal quality factor Q = 2. The low-opacity contours show the habitable zone locations without tidal heating (cf. N. Madhusudhan et al. 2021), and the high-opacity contours show the habitable zone location for our model where tidal heating is included. The dotted and dashed lines denote the optimistic and conservative HZ limits respectively for Earth-like planets according to the model of R. K. Kopparapu et al. (2013). The conservative HZ is bounded by their “Recent Venus” and “Early Mars” cases, while the optimistic HZ is bounded by their “Runaway Greenhouse” and “Maximum Greenhouse” cases. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Status Report, Water/Hycean Worlds & Oceanography

Tides Tighten The Hycean Habitable Zone

by Keith CowingJune 17, 2025June 17, 2025

Hycean planets — exoplanets with substantial water ice layers, deep surface oceans, and hydrogen-rich atmospheres — are thought to be favorable environments for life.

LP 791-18 d, illustrated here, is an Earth-size world about 86 light-years away. The gravitational tug from a more massive planet in the system, shown as a blue dot in the background, may result in internal heating and volcanic eruptions on this exoplanet – as much as Jupiter’s moon Io, the most geologically active body in the Solar System. CREDIT NASA’s Goddard Space Flight Center/Chris Smith (KRBwyle)

Exoplanets, -moons, -comets, Habitable Zones, Status Report

Tidal Dissipation and Synchronization of the Temperate Exo-Earth LP 791-18d

by Keith CowingJune 17, 2025June 17, 2025

The creep tide theory is used to explore several aspects of the tidal evolution of the planetary system of the M-star LP 791-18.

Cassini’s antenna is pointed at the predicted specular point where the angle of incidence (θi) equals the angle of reflection (θr), measured from the local vertical. Right circularly polarized (RCP) signals were transmitted, and at least one of the NASA Deep Space Network (DSN) antennas on Earth captured the echo. At the surface of Titan, a left circularly polarized (LCP) component of the echo signal was generated, requiring the presence on the ground of two receiving channels. Complex samples of each receiver output were collected at 16,000 samples/s and stored for later processing. The purpose of this figure is to illustrate the geometry of the observations and distances on the coordinate axes that are not drawn to scale. -- Nature Communications

Astrogeology, Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Cryobiology, Exoplanets, -moons, -comets, Icy Worlds, Missions & Hardware, Press Release, Titan, Water/Hycean Worlds & Oceanography

New Analysis Of Cassini Data Yields Insights Into Titan’s Seas

by Keith CowingJuly 29, 2024July 29, 2024

A new study of radar experiment data from the Cassini-Huygens mission to Saturn has yielded fresh insights related to the makeup and activity of the liquid hydrocarbon seas near the […]

Enceladus -- NASA

Analog Studies, Arctic / Antarctic / Alpine, Away Teams & Field Reports, Biogeochemical Cycles & Geobiology, Biophysics, Biosignatures & Paleobiology, Enceladus, Europa, Exoplanets, -moons, -comets, Exploration Gear & Tech, Extremeophiles and Extreme Environments, Habitable Zones, Icy Worlds, Imaging & Spectroscopy, Mapping, Geodesy, Cartography, Bathymetry, Microbiology & Virology, Origin & Evolution of Life, Press Release, ROVs/Submersibles/Diving, Water/Hycean Worlds & Oceanography

Hydrothermal Vents On The Seafloors Of Ocean Worlds Could Support Life

by Keith CowingJune 25, 2024June 25, 2024

We’ve all seen the surreal footage in nature documentaries showing hydrothermal vents on the frigid ocean floor—bellowing black plumes of super-hot water—and the life forms that cling to them. Now, […]

Simulations of the 2:1 mean-motion resonance crossing between the coorbitals Janus and Epimetheus and Enceladus using simpl. Enceladus and Dione were assumed to be on their current orbits, while Janus and Epimetheus were shifted inward. In the left-hand side panels Janus and Epimetheus were in their current horseshoe configuration, while they were put in a tadpole (Trojan) configuration in the right-hand panels. The coorbitals’ orbits are expanding due to an artificial acceleration meant to represent ring torques. We used k2/Q = 0.01 for Enceladus, and we ignored satellite tides for the coorbitals. -- astro-ph.EP

Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Enceladus, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

A Past Episode of Rapid Tidal Evolution of Enceladus?

by Keith CowingJune 14, 2023October 7, 2025

Saturn possesses a dynamically rich system containing numerous moons and impressive rings. Whether the rings of Saturn are much younger than the planet itself has been a long-open question; more […]