ice giant Archives

Reprocessed images of Uranus [L]] and Neptune [R] NASA/JPL-Caltech (Uranus and Neptune); “Modelling the Seasonal Cycle of Uranus’s Colour and Magnitude, and Comparison with Neptune,” by Patrick G. J. Irwin et al., in Monthly Notices of the Royal Astronomical Society, Vol. 527, No. 4; February 2024 (reprocessed images)

Astrogeology, Atmospheres, Climate, Weather, Ice Giant, Icy Worlds, Imaging & Spectroscopy, Neptune, Status Report, Uranus

Different Inhomogeneous Evolutionary Histories for Uranus and Neptune

by Keith CowingJune 19, 2025

We present updated non-adiabatic and inhomogeneous evolution models for Uranus and Neptune, employing an interior composition of methane, ammonia, water, and rocks.

Binary collision-induced H2–He absorption coefficient, α, normalized by the hydrogen and helium gas densities, as function of frequency in the fundamental band, at 296 K. The parato-ortho distribution, is representative of equilibrium H2, just as in Fig. 2. Our model (“this work”), is compared with the model of Abel et al.17 for T = 300K, and with the laboratory measurements of Vitali et al. 18 and Brodbeck et al.19 , both of which were made near 296 K. We note that neither our model nor that of Abel et al. considered the discrete, intercollisional interference dips present in the laboratory spectra. -- astro-ph.EP

Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Gas Giants, Ice Giant, Jupiter, Neptune, Saturn, Status Report, Uranus

Improved H2-He and H2-H2 Collision-Induced Absorption Models and Application to Outer-Planet Atmospheres

by Keith CowingJune 15, 2025June 13, 2025

Using state-of-the-art ab initio interaction-induced dipole and potential-energy surfaces for hydrogen-helium (H2-He) pairs, we compute the rototranslational collision-induced absorption coefficient at 40-400 K for frequencies covering 0-4000 cm-1.

Exoplanets with masses error and radii error less than 25%. Symbol size is proportional to mass. Colors correspond to equilibrium temperatures calculated with bond albedos of 0.3 and redistribution factors of 4. Colors are loosely binned according to physical processes: planets with icy surfaces should they have any water (0-273 K), planets that allow for liquid water (273-373 K), planets that are in runaway greenhouse below the critical point of water (373-670K), hot planets that cannot have water clouds (670-1200K) and magnetic effects on their atmospheres are negligible, hot planets where magnetic effects like ohmic dissipation are important, very hot planets where magnetic effects are less important (due to full ionization and freezing to magnetic field). Solar system planets are labeled and shown as black symbols for reference. -- astro-ph.EP

Astrochemistry, Astrogeology, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Exoplanets, -moons, -comets, Gaia - Planetary Perspectives, Gas Giants, Ice Giant, Icy Worlds, Status Report, Water/Hycean Worlds & Oceanography

Diversity Of Exoplanets

by Keith CowingMay 16, 2025

This review article delves into the study of low-mass exoplanets: super-Earths, mini-Neptunes and the new categories within and between that we are starting to discover.

This rendering demonstrates what is happening during a stellar occultation and illustrates an example of the light curve data graph recorded by scientists that enables them to gather atmospheric measurements, like temperature and pressure, from Uranus as the amount of starlight changes when the planet eclipses the star. NASA/Langley Research Center Advanced Concepts Laboratory Video

Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Ice Giant, Icy Worlds, Imaging & Spectroscopy, Press Release, Uranus

Using Stellar Occultation To Study The Atmosphere Of Ice Giant Uranus

by Keith CowingMay 13, 2025

When a planet’s orbit brings it between Earth and a distant star, it’s more than just a cosmic game of hide and seek. It’s an opportunity for NASA to improve […]

This image of Uranus from NIRCam (Near-Infrared Camera) on the NASA/ESA/CSA James Webb Space Telescope shows the planet and its rings in new clarity. The Webb image exquisitely captures Uranus’s seasonal north polar cap, including the bright, white, inner cap and the dark lane in the bottom of the polar cap. Uranus’ dim inner and outer rings are also visible in this image, including the elusive Zeta ring—the extremely faint and diffuse ring closest to the planet. Larger image

Atmospheres, Climate, Weather, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Ice Giant, Status Report, Uranus

Uranus Flagship Science-Driven Tour Design: Community Input Poll

by Keith CowingMay 12, 2025May 12, 2025

The highest priority Planetary Flagship from the Planetary Science and Astrobiology Decadal Survey is the Uranus Orbiter and Probe.

Sketches of the two end-members of possible bulk compositions of Uranus and Neptune: a water-dominated interior (left) and a rock-dominated interior (right). The dark brown at the planetary center represents the core, which is expected to be composed of iron and rocks. The atmosphere is represented with gray. Note that the transition between different layers may be fuzzy and that currently it is still unknown whether the planetary interiors are differentiated with distinct compositional layers. Keck Institute for Space Studies / Chuck Carter

Astrochemistry, Atmospheres, Climate, Weather, Exploration Gear & Tech, Gas Giants, Icy Worlds, Neptune, Status Report, Uranus

Ice Giants

by Keith CowingApril 29, 2025April 29, 2025

Uranus and Neptune, the so-called “ice giants”, represent a fascinating class of planets. They are the outermost planets in the solar system with intermediate masses/sizes, complex non-polar magnetic fields, strong […]

At the left, an enhanced-color image of Neptune from NASA’s Hubble Space Telescope. At the right, that image is combined with data from NASA’s James Webb Space Telescope. The cyan splotches, which represent auroral activity, and white clouds, are data from Webb’s Near-Infrared Spectrograph (NIRSpec), overlayed on top of the full image of the planet from Hubble’s Wide Field Camera 3. - STSCI

Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Ice Giant, Icy Worlds, Imaging & Spectroscopy, Neptune, People Of Astrobiology, Press Release, Radiation, Space Weather & Heliophysics

Webb Space Telescope Captures Neptune’s Auroras For First Time

by Keith CowingApril 4, 2025May 12, 2025

For the first time, NASA’s James Webb Space Telescope has captured bright auroral activity on Neptune. Auroras occur when energetic particles, often originating from the Sun, become trapped in a […]

Looking at ice-giant planet Uranus over the course of 20 years - STSCI

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Ice Giant, Icy Worlds, Imaging & Spectroscopy, Press Release, Uranus, Water/Hycean Worlds & Oceanography

20-Year Hubble Study of Uranus Yields New Atmospheric Insights

by Keith CowingApril 2, 2025May 12, 2025

The ice-giant planet Uranus, which travels around the Sun tipped on its side, is a weird and mysterious world. Now, in an unprecedented study spanning two decades, researchers using NASA’s […]

Uranus P-T profiles plotted over H2O phase diagram.

Atmospheres, Climate, Weather, Ice Giant, Icy Worlds, Missions & Hardware, Status Report, Uranus

Interior and Gravity Field Models for Uranus Suggest Mixed-composition Interior: Implications for the Uranus Orbiter and Probe

by Keith CowingDecember 28, 2024May 12, 2025

The interior composition and structure of Uranus are ambiguous. It is unclear whether Uranus is composed of fully differentiated layers dominated by an icy mantle or has smooth compositional gradients.

Models for the interior structures of the ice-giant planets Uranus and Neptune have two distinct, intermediate layers: an upper, water-rich convecting layer where disorganized magnetic fields are generated, and a lower, non-convecting hydrocarbon-rich layer. New computer simulations show that icy materials naturally separate at high pressure and temperature into these two layers. Credit Burkhard Militzer, UC Berkeley

Astrogeology, Atmospheres, Climate, Weather, Ice Giant, Icy Worlds, Neptune, Press Release, Uranus, Water/Hycean Worlds & Oceanography

A Clue To What Lies Beneath The Bland Surfaces Of Uranus And Neptune

by Keith CowingNovember 26, 2024May 12, 2025

Diamond rain? Super-ionic water? These are just two proposals that planetary scientists have come up with for what lies beneath the thick, bluish, hydrogen-and-helium atmospheres of Uranus and Neptune, our […]