[The Planetary Science Journal] The native ice composition of Halley-type Comet 13P/Olbers (hereafter 13P) was measured post-perihelion, on UT 2024 August 16 using iSHELL, the 1─5 μm cross-dispersed, high-resolution facility […]
astrochemistry
![Effect of substrate morphology and composition on the UV photodesorption of water ice at 12 K. (A) Evolution of the XPS-derived ice coverage as a function of photon fluence for an initial coverage of approximately 4 ML deposited on planar gold, planar olivine crystal, olivine microparticle powder, and soot at 12 K. Linear fits to the coverage curves give photodesorption yields of 1.5 × 10−3 , 1.8 × 10−3 , 7.2 × 10−4 , and 7.2 × 10−5 molecule photon−1 , respectively (see Table 1). (B) Scanning electron microscopy image of the olivine powder film, showing micrometer- and submicrometer-sized angular particles. (C) Scanning electron microscopy image of the soot film, showing highly aggregated carbon nanoparticles with a much finer and more ramified morphology. (D) Coverage derived from XPS measurements as a function of UV fluence at 12 K for 2 ML ice films deposited at 120 K (nonporous ice) and 12 K (porous ice), giving photodesorption yields of 4.6 × 10−5 and 1.4 × 10−5 molecule photon−1 , respectively -- [astro-ph.IM]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/11/Suppression.png?resize=1200%2C720&ssl=1)
Posted inAstrochemistry
Suppression of Water-ice UV Photodesorption On Cosmic Dust Analogs
[astro-ph.IM] Ultraviolet (UV) photodesorption regulates the partitioning of water between interstellar ice mantles and the gas phase, yet laboratory yields are generally measured on planar substrates rather than on surfaces […]
Posted inAstrochemistry
Astrochemistry: Hubble and JWST Observe Star Formation in The Carina Nebula
[ESA] The NASA/ESA Hubble and the NASA/ESA/CSA James Webb Space Telescopes recently stared at an eerie star-forming scene within the Carina Nebula, a massive gas and dust cloud located approximately […]
![The PES for the reaction of C6H6 with CP in kcal mol−1 . Values in gray were calculated using CCSD(T)-F12c/cc-pVTZ-F12//ωB97X-2(TQZ)-D3(BJ)/ma-def2-TZVPP, those in orange were found using DFT alone (ωB97X-2(TQZ)-D3(BJ)/ma-def2-TZVPP), and those in navy blue were found using CCSD(T)-F12c/cc-pVTZ-F12//M06-2X-D3(0)/ma-def2-TZVPP. The dashed gray and navy lines corresponds to the identified transition states in the calculations which employed ωB97X-2(TQZ) and M06-2X, respectively. Meanwhile, the dotted black line represents the barrierless CP addition to benzene found from the relaxed scans that used ωB97X, ωB97M, and B2PLYP. -- [astro-ph.GA]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/11/A-Potential.png?resize=1200%2C720&ssl=1)
Posted inAstrochemistry
A Potential New Dimension of Astrophysical Aromatic Functionalization: Phosphaethynyl (CP) Derivatives
[astro-ph.GA] Quantum chemical computations outline a thermodynamically viable, low-temperature, gas-phase formation pathway for phosphaethynyl cyclopropenylidene (c-C3HCP), resulting from cyclopropenylidene (c-C3H2) and the phosphaethynyl (CP) radical.
![Panels a and c display the C3H + 3 ion signal from the dissociative photoionization of allene and propyne, respectively. Panels b and d show the reaction cross sections (left axis) and rate coefficients (right axis) with C2H4 , as a function of photon energy. The secondary x-axes indicate the maximum internal energy deposited in the system for the cyclic (top axis) and the linear (bottom axis) of C3H + 3 . -- [physics.chem-ph]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/11/Gasphase.png?resize=1200%2C719&ssl=1)
Posted inAstrochemistry
Gas-phase Chemistry of C3H+3: a Key Building Block for Carbon Mass Growth in Space
[physics.chem-ph] The gas-phase chemistry of C3H+3 plays a central role in the growth of carbonaceous species across a wide range of environments, from combustion systems to interstellar media.
![Comparison of the averages of the Bennu aggregate samples (OREX-800033-0, OREX-800117-0, OREX-800107-0) from four different laboratories. Concentrations are double-normalized to Mg and the literature average values for CI chondrites (Lodders et al., 2025a). The uncertainties shown are ±1 SD. Elements that deviate by more than 20% from the CI average are labeled. Four extreme outliers from individual analyses have been excluded (see Table 7) and are not shown in this figure. - -[astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/11/Best-Bulk-Bennu.png?resize=1200%2C719&ssl=1)
Posted inAstrogeology
Best Bulk Bennu (B3): Elemental Compositions Of Aggregate Samples From Asteroid Bennu K.
[astro-ph.EP] Ivuna-type (CI) carbonaceous chondrites have long served as proxies for the bulk Solar System composition due to their close agreement with solar photospheric abundances and enrichment in volatile elements […]
Posted inAstrochemistry
Sulfur Dioxide Sulfide (SSO2): The Elusive Isovalent Analogue of Sulfur Trioxide (SO3)
[The Journal of Physical Chemistry Letters]. Sulfur dioxide sulfide (SSO2) has remained experimentally undetected despite repeated theoretical predictions of its stability.
![Example fits to the observed spectrum of GJ 436 (Teff = 3495 K, [Fe/H] = -0.05 dex, 2023 observation), LHS 1140 (Teff = 3111 K, [Fe/H] = –0.07 dex), and TOI 2290 (Teff = 3758 K, [Fe/H] = –0.18 dex) are shown as solid purple, gold, and cyan points, respectively. GJ 436 and LHS 1140 spectra were obtained with IGRINS while the TOI 2290 spectrum was obtained with NIRSPEC. The FeH line falls in an order gap for our NIRSPEC spectra and is not shown in this figure. Best fitting synthetic spectra are shown as dashed lines. Synthetic spectra creation and fitting methodology is described in section 3.-- [astro-ph.SR]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/11/The-Composition.png?resize=1200%2C752&ssl=1)
Posted inExoplanets, -moons, -comets
The Composition of M-dwarf Exoplanet Hosts: Atmospheric Parameters and O, Mg, Si, and Fe Abundances from IR Spectroscopy
[astro-ph.SR] Determining M-dwarf abundances is an important step to discerning the chemical evolution of the Milky Way and characterizing exoplanetary systems, especially since these objects commonly host small exoplanets.
Posted inAstrochemistry
Formamide Formation on Forsterite and Mg(OH)2.H2O
[astro-ph.GA] Context. Formamide formation in the Universe has been the subject of debate due to its importance as a precursor to amino acids and RNA. Current studies focus on the […]
Posted inAstrochemistry
Pre-Accretion Formation of Sulfuric Acid in Interstellar Ice Analogs: Implications for Sulfate in Ryugu and Bennu
[The Journal of Physical Chemistry Letters] Sulfate-bearing phases and soluble sulfate species, including sodium sulfate (Na2SO4), in carbonaceous asteroids are commonly attributed to parent-body aqueous alteration, yet the formation of […]