![The green-to-red intensity ratio of [O I] (G/R) in 3I (filled circle), compared with measurements for a sample of Solar System comets: Jupiter-family comets (JFCs; open triangles), Oort Cloud comets (OCCs; open squares), and Halley-type comets (HTCs; crosses) from A. Decock et al. (2013); A. McKay et al. (2015); Y. Shinnaka & H. Kawakita (2016); Y. Shinnaka et al. (2020), as well as C/2016 R2 from C. Opitom et al. (2019) and 2I/Borisov from C. Opitom et al. (2021). -- astro-ph.GA](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/03/A-post-perihelion-constraint.png?resize=1200%2C719&ssl=1)
We present high-resolution optical spectroscopy of interstellar comet 3I/ATLAS (C/2025 N1) obtained with the High Dispersion Spectrograph mounted on the Subaru Telescope on UT 2026 January 7, when the comet […]
We report a survey of molecular emission from cometary volatiles using the James Webb Space Telescope (JWST) toward interstellar object 3I/ATLAS carried out on UT 2025 December 22 and 23 […]
Active small bodies in extrasolar systems, the extrasolar analogues of Solar System comets, provide insights into the orbital evolution and physical processes shaping planetary systems.
Neptune’s present axial tilt of approximately 28 deg. with respect to its orbital plane can be explained by collisions that its primordial core may have experienced with surrounding planetary embryos […]
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.
Interstellar objects provide the only directly observable samples of icy planetesimals formed around other stars, and can therefore provide insight into the diversity of physical and chemical conditions occurring during […]
Competing processes shape Europa’s surface: geological activity replenishes material through resurfacing, while bombardment by charged particles alters surface chemical composition. Each process leaves distinct spectral signatures.
We investigate the magnetic signature of oceanic circulation in Ganymede’s subsurface ocean using kinematic induction modeling. Our approach couples zonal jet flows from rotating thermal convection simulations with magnetic field […]
China’s Tianwen-1 Mars orbiter successfully imaged the third interstellar object, 3I/ATLAS, during its close encounter with Mars using the onboard HiRIC CMOS camera. This is China’s first deep-space observation of […]
A team of researchers from the UK and Korea has reached the most inaccessible and least-understood part of Thwaites Glacier in West Antarctica where they will drill through the glacier […]
