![Estimated total mass of transiting compact systems, Mtot, scaled to the stellar mass, M∗. a, (Mtot/M∗) for compact systems having ≥ 3 known planets that orbit a single star within a < 0.5 au (circle markers, blue box). Points are ordered left-to-right by ascending stellar mass. Data are from www.exoplanetarchive.ipac.caltech.edu. For cases without mass estimates, we use the observed planet radius, increase the estimated radius uncertainty by a factor of 2, and then apply a radius vs. mass relation [46]. Light [medium] blue circles are systems with all [some] planetary masses estimated from this relation, while dark blue circles are systems with measured planetary masses. We include only systems with resulting errors ∆Mtot/Mtot < 1. b, Distribution of compact system mass ratios. Over a wide range of stellar masses (M∗ ∼ 0.1 to 1.3 stellar mass), compact multi-planet systems display a common mass ratio, with 90% of systems having 3×10−5 < (Mtot/M∗) < 3×10−4 (gray shaded region). This mass ratio is more similar to that of the gas giant satellite systems (square markers, yellow box) than to the inner or outer planets in our Solar System (triangle markers, red box). -- astro-ph.EP](https://i0.wp.com/astrobiology.com/wp-content/uploads/2025/06/Origin-of-compact-exoplanetary.png?resize=1200%2C718&ssl=1)
Exoplanetary systems that contain multiple planets on short-period orbits appear to be prevalent in the current observed exoplanetary population, yet the processes that give rise to such configurations remain poorly […]
Comets and Asteroids
Posted inAstrochemistry, Astrogeology, Astronomy & Telescopes, Biogeochemical Cycles & Geobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Status Report
Water Production Rates from SOHO/SWAN Observations of Comets C/2017 K2 (PanSTARRS) and C/2022 E3 (ZTF)
In 2022 and 2023 the hydrogen comae of two long period comets, C/2017 K2 (PanSTARRS) and C/2022 E3 (ZTF), were observed with the Solar Wind ANisotropies (SWAN) all-sky hydrogen Lyman-alpha […]
![[LEFT] 2018-07-17. Image taken with the Asiago Schmidt telescope with B, g, r filters. Comet Giacobini-Zinner moves fast in a very starrich field in the constellation Cygnus. The dust tail, which is reddened by the reflection of sunlight, is directed South-West, whereas the blue-green coma develops in a sphere around the nucleus. [RIGHT] 2018-08-08. A mathematical filter was applied to the original image, to highlight the morphology of the inner coma dominated by jet structures directed towards the Sun. These derive from small active areas placed on the nucleus. The tail develops in an antisolar direction. Image taken with the Asiago Schmidt telescope. -- astro-ph.EP](https://i0.wp.com/astrobiology.com/wp-content/uploads/2025/05/ASIACO-Asiago-Spectroscopy.png?resize=1200%2C721&ssl=1)
Posted inAstrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Status Report
ASIACO: Asiago Spectroscopy and Imaging Atlas of Comets
The ASIACO project is an atlas of cometary imaging and spectroscopy obtained from the Asiago Astrophysical Observatory between 2012 and 2024, still ongoing.
Posted inAstrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Status Report
First Detection of Molecular Activity in the Largest Known Oort Cloud Comet: ALMA Imaging of C/2014 UN271 (Bernardinelli-Bernstein) At 16.6 au From The Sun
We report observations of comet C/2014 UN271 (Bernardinelli-Bernstein) carried out on UT 2024 March 8 and 17 at a heliocentric distance (rH) of 16.6 au using the Atacama Large Millimeter/Submillimeter […]
Posted inAnalog Studies, Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biophysics, Biosignatures & Paleobiology, Comets and Asteroids, Imaging & Spectroscopy, Impact events, Interstellar, Mapping, Geodesy, Cartography, Bathymetry, Meteorites & Asteroids, Moon, Status Report
Polycyclic Aromatics In The Chang’E 5 Lunar Soils
Polycyclic aromatics are ubiquitous in the interstellar medium and meteorites, yet the search for lunar polycyclic aromatics remains a significant challenge.
Posted inAstrochemistry, Astrogeology, Astronomy & Telescopes, Beta Pictoris, Comets and Asteroids, Exoplanets, -moons, -comets, Icy Worlds, Imaging & Spectroscopy, Status Report
Upper Limits On CN From Exocomets Transiting Beta Pictoris
The young (23 Myr) nearby (19.4 pc) star β Pictoris hosts an edge-on debris disk with two gas giant exoplanets in orbit around it. Many transient absorption features have been […]
Posted inAstrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Status Report
Activity-Induced Near-Infrared Variability at 29P/Schwassmann-Wachmann 1, 2017-2022
29P/Schwassmann-Wachmann 1 (SW1) is both the first-discovered active Centaur and the most outburst-prone comet known.
![Orbital distribution of 7,982 impacts detected by EDMOND, CAMS, GMN, FRIPON, and EFN networks. Each impact is estimated to be equal to or greater than 10 g (diameter ⪆2 cm) at the top of the atmosphere. Orbital distribution is normalized to the impact probability, as calculated using the method of Pokorn`y and Vokrouhlick`y [96]. Despite this, there still exists a concentration of meteoroids on orbits with q∼1 au -- astro-ph.EP](https://i0.wp.com/astrobiology.com/wp-content/uploads/2025/04/Perihelion-History-And-Atmospheric-Survival.png?resize=1200%2C721&ssl=1)
Posted inAstrochemistry, Astrogeology, Biosignatures & Paleobiology, Comets and Asteroids, Meteorites & Asteroids, Status Report
Perihelion History And Atmospheric Survival As Primary Drivers Of The Earth’s Meteorite Record
Models predict that more than half of all impacting meteoroids should be carbonaceous, reflecting the abundance of carbon-rich asteroids in the main belt and near-Earth space.
Posted inAstrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Imaging & Spectroscopy, Planetary Protection & Biosafety, Sample Return, Status Report
NASA Astromaterials: OSIRIS-REx News April 2025
The OSIRIS-REx curation team has continued to expand and enrich the NASA OSIRIS-REx catalog – this newsletter includes the second update of the catalog since its initial publication in March […]
Posted inComets and Asteroids, Exoplanets, -moons, -comets, Extinction events, Gaia - Planetary Perspectives, Impact events, Origin & Evolution of Life, Status Report
The Atmospheric Entry of Cometary Impactors
Cometary impacts play an important role in the early evolution of Earth, and other terrestrial exoplanets.