Kuiper belt objects Archives

Spectral characterization of Chiron’s surface composition. a Comparison of the bestfit spectral model of the surface composition (red) with the measured spectrum (black). The surface is best described by an intimate mixture of water ice in both amorphous and crystalline phases, carbon dioxide ice, and tholin-like materials. b Residuals between the model and the data show an excellent fit, with a root mean square deviation that is just 1% higher than the average scatter in the data. c Zoomed-in view of the complex organic absorption feature spanning 3.3–3.6 µm, with the individual component bands indicated by dashed lines. Comparison between the measured spectrum and synthetic spectra of several candidate species, convolved to the spectral resolution of the data, points to C3H8 and/or ice tholins produced by the irradiation of H2O ice and C2H6 as the most plausible candidates for the observed organic feature. -- astro-ph.EP

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Status Report

JWST Reveals Anomalously Enhanced Methane Outgassing From Below Chiron’s Water Ice And Carbon Dioxide Bearing Surface

by Keith CowingMay 26, 2026May 26, 2026

Centaurs are inward-scattered Kuiper belt objects, with some exhibiting comet-like activity. The physical mechanisms powering this activity remain poorly understood, with carbon monoxide (CO) sublimation or the crystallization of amorphous […]

Details of the interior models of Uranus and Neptune. Top: Illustration of the three-layer internal structure model assumed. Both the envelope and mantle contain hydrogen, helium, ices, and rocks, with the mantle expected to have a higher concentration of ices and rocks. The core is composed entirely of rocks. Bottom: Envelope metallicity versus mantle metallicity for interior models of Uranus and Neptune. Each dot represents a model that fits both the gravitational data and radius of the respective planet. The color scale indicates the core mass. -- astro-ph.EP

Astrogeology, Exoplanets, -moons, -comets, Ice Giant, Icy Worlds, Neptune, Status Report, Uranus

Reassessing Planetary Composition: Evidence Of Rock-dominated Envelopes In Uranus And Neptune

by Keith CowingApril 17, 2026April 17, 2026

Although Uranus and Neptune are commonly classified as ice giants, their exact compositions remain poorly constrained. Recent studies of outer Solar System bodies challenge the traditional view that these planets […]

Kuiper belt objects

JWST Reveals Anomalously Enhanced Methane Outgassing From Below Chiron’s Water Ice And Carbon Dioxide Bearing Surface

Reassessing Planetary Composition: Evidence Of Rock-dominated Envelopes In Uranus And Neptune

ALMA Central Molecular Zone Exploration Survey (ACES) I: Overview

RNA And Proteins Joined Up At The Origins Of Life: Persistence Is The Point

Selection For Growth Drives The Emergence Of Genetic Heredity In Protocells

NASA SMD ROSES-25 Amendment 65: New Opportunity: C.4 Planetary Science Enabling Facilities

TESS Photometry and Radial Velocity Analysis of the sub-Neptune Exoplanet π Mensae c and the Wider π Mensae Planetary System