![A symbiotic scenario for co-evolution of the ribosome and the replicase. Two variations of the scenario are depicted, whereby the peptidyltransferase center (PTC) and the replicase (REP) ribozymes are encoded by distinct (A) or the same (B) RNA molecule. The figure depicts three major stages of cellular evolution from the primordial RNA world (left) to the intermediate RNA-protein world (center) and the last universal cellular ancestor (LUCA, right). The major events occurring during each stage are briefly described in the corresponding information boxes at the bottom of the figure. -- [q-bio.PE]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/The-selfish.png?resize=1200%2C712&ssl=1)
[q-bio.PE]. The ribosome is responsible for protein synthesis in all cells, and is the largest energy consumer in the cell.
Biochemistry & Organic Chemistry
Posted inAstrochemistry
Interstellar Aromatic Infrared Bands: IR Absorption Spectroscopy Of The Lowest Triplet State Of Naphthalene
[astro-ph.GA] The aromatic infrared bands (AIBs), emission features observed ubiquitously across a wide variety of interstellar objects, are commonly attributed to radiative cooling of highly-excited ground-state vibrational levels of polycyclic […]
![Images acquired on 2019 October 4 (left) and 27 (right) with LDT. The top row show stacks of r and CN images, respectively. The bottom row shows the same images enhanced by subtraction of an azimuthal median profile. The enhanced CN images have been smoothed with a Gaussian profile to better reveal the faint underlying structure. A compass indicating north (N), east (E), the anti-sunward direction (−⊙), and the anti-velocity vector (−v) are overlaid on the r panels, while a scale bar showing a distance at the comet of 20,000 km is given on the CN panels (1 arcsec corresponds to 2134 km on October 4 and 1814 km on October 27). All four panels for a given night have the same orientation and physical scale at the comet. The October 4 image is a single frame and shows several artifacts that could not be removed without a median combination include several bright pixels in the CN frame (yellow) and a bad column in all frames (black diagonal line). On October 4, a bright star is seen near the left edge of the r frames and as a diagonal (yellow) line in the upper right in CN. Two faint trailed stars are visible in the r images on October 27. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/The-Highly.png?resize=1200%2C720&ssl=1)
Posted inComets and Asteroids
The Highly Unusual Behavior And Chemical Composition Of Interstellar Comet 2I/Borisov
[astro-ph.EP]. We report on imaging, spectroscopy, and narrowband photometry of interstellar comet 2I/Borisov obtained at Lowell Observatory from 2019 September 13 to December 16.
Posted inAstrochemistry
Slow-electron-triggered Chemistry In Interstellar Methanol-water Ices
[Astronomy & Astrophysics] Water and, to a lesser extent, methanol are widespread in interstellar space as ices, where sustained exposure to ionizing radiation promotes the formation of complex compounds such […]
![Occam’s razor-based deconvolution result of the subset of signals associated with CnHmN parent and fragment species detected by the DFMS on 3 August 2015. The measured signals (measured) are given in arbitrary units (a. u.) with 30 % error margins. The different contributions of the chosen candidate molecules are colour-coded according to their molecular structure – in shades of red and purple for chain-based molecules and in shades of green and blue for cyclic molecules. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/Nitrogen.png?resize=1200%2C707&ssl=1)
Posted inComets and Asteroids
Nitrogen- And Nitrogen-oxygen-bearing Organic Molecules In Comet 67P/Churyumov-Gerasimenko: An Untargeted Investigation
[astro-ph.EP] Comets provide a unique window into the history of the Solar System as they carry some of the best-preserved material and make it available to in situ exploration.
Posted inOrigin & Evolution of Life
Crossing The Functional Desert: Cascade-Driven Assembly And Feasibility Transitions In Early Life
[physics.soc-ph] The origin of life poses a problem of combinatorial feasibility: How can temporally supported functional organization arise in exponentially branching assembly spaces when unguided exploration behaves as a memoryless […]
![Graphical abstract -- [The Journal of Membrane Biology]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/From-Meteorites.png?resize=1200%2C712&ssl=1)
Posted inBiochemistry & Organic Chemistry
From Meteorites to Membrane Rafts: Ganglioside-Incorporating Prebiotic Vesicles and the Emergence of Membrane Domain Organization
[The Journal of Membrane Biology] Life requires membranes. But what were the first membranes made of, and how did they acquire the functional complexity of modern cells?
![The origin of life is the first, arguably, the most important and also the most enigmatic major transition in evolution (MTE). [q-bio.PE]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/The-first.png?resize=1200%2C718&ssl=1)
Posted inOrigin & Evolution of Life
The First Major Transition: Origin Of Life From A Multilevel Selection Perspective
[q-bio.PE] As all MTE, the transition at the origin of life can be constructively addressed only within the conceptual framework of multilevel selection. The two levels of selection relevant for […]
![Upper Panels. Maps of N × ρ for ortho-H2O and para-H2O, the derived OPR, and Trot(H2O) for the 6 µm band measured on February 28. Note that N for each species has been corrected for the derived OPR. Lower Panels. As in the upper panels for the 2.6 µm H2O bands measured on March 1. -- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/JWST-Spatial.png?resize=1200%2C727&ssl=1)
Posted inComets and Asteroids
JWST Spatial-Spectral Mapping of Green Comet C/2022 E3 (ZTF)
[astro-ph.EP] We report a survey of molecular emission from cometary volatiles using the James Webb Space Telescope (JWST) toward Oort cloud comet C/2022 E3 (ZTF) carried out on UT 2023 […]
![Example of the stacking procedure for the Maidanak data obtained on 2025 August 15, based on ten 60 s exposures in each of the B, V , and R filters. Left: Comet-centered stack, showing the coma morphology without trailing of the comet signal. The pink circle indicates an aperture radius of 10 000 km. Right: Sidereal stack used for photometric calibration, in which the comet appears trailed.-- [astro-ph.EP]](https://i0.wp.com/astrobiology.com/wp-content/uploads/2026/08/The-Inbound.png?resize=1200%2C720&ssl=1)
Posted inComets and Asteroids
The Inbound Gas and Dust Evolution of Interstellar Comet 3I/ATLAS from Optical Spectroscopy and Multi-band Photometry
[astro-ph.EP] Interstellar objects (ISOs) provide direct constraints on the composition and evolution of extrasolar planetary systems. As the third confirmed ISO, comet 3I/ATLAS offers a rare opportunity to study pristine […]