Comets and Asteroids Archives

Carbon to silicon atom ratios in comets and other objects, from Woodward et al. (2021). -- astro-ph.EP

Astrochemistry, Astrogeology, Biosignatures & Paleobiology, Comets and Asteroids, Impact events, Meteorites & Asteroids, Missions & Hardware, Status Report

Comet 81P/Wild 2: A Record of the Solar System’s Wild Youth

by Keith CowingDecember 2, 2023December 2, 2023

NASA’s Stardust mission returned rocky material from the coma of comet 81P/Wild 2 (pronounced “Vilt 2”) to Earth for laboratory study on January 15, 2006. Comet Wild 2 contains volatile […]

a, Backscattered electron image of a fine Ryugu grain. The white boxes correspond to the areas shown in b and c. b, Secondary electron image of framboidal magnetite showing granular texture. c, Secondary electron image of porous iron sulfide surrounded by phyllosilicate. The arrow points to an iron whisker on the iron sulfide surface. Sample ID is A0104-021012.

Astrochemistry, Astrogeology, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Comets and Asteroids, Meteorites & Asteroids, Origin & Evolution of Life, Press Release

Meteorites Were A Likely Source Of Nitrogen For Early Earth

by Keith CowingDecember 2, 2023December 2, 2023

Micrometeorites originating from icy celestial bodies in the outer Solar System may be responsible for transporting nitrogen to the near-Earth region in the early days of our solar system. That […]

Left: This image shows an oblique view of the Aswan collapse site. Five months after the collapse it clearly stands out as a substantially brighter region. The normal albedo is 0.17 ± 0.01 (Pajola et al. 2017a) and the current modelling suggests that dust and water ice near the intrinsic nucleus mixing ratio was exposed at this time (but no CO2 ice). Image MTP024 / n20151226t170504370id4df22.img (Sierks & the OSIRIS Team 2018b) was acquired on 2015 December 26 with ∼ 1.4 m px−1 resolution when Rosetta was 77.0 km from the comet. Right: This is a face–on view of the cliff showing that the brightness of the scar is significantly reduced, yet somewhat higher than for the surroundings eleven months after collapse. At this point the current modelling suggests a ∼ 0.5 mm dust mantle, i. e., so thin that some reflection of the water ice still might reach the surface. Image MTP030 / n20160608t143426745id4df22.img (Sierks & the OSIRIS Team 2018c) was acquired on 2016 June 8 with ∼ 0.5 m px−1 resolution when Rosetta was 29.7 km from the comet. -- astro-ph.EP

Astrochemistry, Astrogeology, Comets and Asteroids, Icy Worlds, Meteorites & Asteroids, Status Report

Cliff Collapse On Comet 67P/Churyumov-Gerasimenko – I. Aswan

by Keith CowingNovember 25, 2023November 25, 2023

The Aswan cliff on Comet 67P/Churyumov-Gerasimenko collapsed on 2015 July 10. Thereby, relatively pristine comet material from a depth of ~12 m was exposed at the surface. Observations of the […]

Examples of median-averaged IFU slices obtained with the G235M grating setting for Patroclus and Eurybates. The slices are projected onto the sky plane, with the x and y coordinates corresponding to right ascension and declination, respectively. A logarithmic stretch has been applied to the flux scaling in order to accentuate the detailed structure of the target PSFs at wide separations. The PSF of the Patroclus binary shows an extended shape. The black boxes denote the extraction regions used in producing the spectra. The faint background source near Patroclus lies in a region of the field of view that was masked during our spectral extraction. -- astro-ph.EP

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

JWST Near-infrared Spectroscopy Of The Lucy Jupiter Trojan Flyby Targets: Evidence For OH Absorption, Aliphatic Organics, And CO2

by Keith CowingNovember 23, 2023November 22, 2023

We present JWST/NIRSpec observations of the five Jupiter Trojans that will be visited by the Lucy spacecraft — the Patroclus–Menoetius binary, Eurybates, Orus, Leucus, and Polymele.

Optical spectrum of comet 46P/Wirtanen observed from Mt. Abu observatory. -- astro-ph.EP

Astrochemistry, Comets and Asteroids, Imaging & Spectroscopy, Status Report

Optical Spectroscopy Of Comets

by Keith CowingNovember 20, 2023November 20, 2023

Comets are pristine remnants of the Solar system, composed of dust and ice. They remain inactive and undetectable for most of their orbit due to low temperatures. However, as they […]

This artwork shows a rocky planet being bombarded by comets. Image credit: NASA/JPL-Caltech

Astrochemistry, Astrogeology, Comets and Asteroids, Panspermia, Press Release

Bouncing Comets Could Deliver Building Blocks For Life To Exoplanets

by Keith CowingNovember 16, 2023November 16, 2023

How did the molecular building blocks for life end up on Earth? One long-standing theory is that they could have been delivered by comets. Now, researchers from the University of […]

12CO+ and 13CO+ theoretical spectra superimposed to the observational data obtained on comet C/2016 R2. The relative intensity of 13CO+ emission lines are based on the 12CO+ fit of the emission lines. They do not respect the intensities observed in this comet, the purpose of this plot being only to show the wavelength shift between the emission lines of these two isotopologues. -- astro-ph.EP

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

Comets 12CO+ and 13CO+ Fluorescence Models For Measuring The 12C/13C Isotopic Ratio In CO+

by Keith CowingNovember 13, 2023November 13, 2023

Context: CO is an abundant species in comets, creating CO+ ion with emission lines that can be observed in the optical spectral range. A good modeling of its fluorescence spectrum […]

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Comets and Asteroids, Missions & Hardware, Press Release

Exploring The Origin Of Nucleosynthetic Isotope Variations In Ryugu Samples

by Keith CowingNovember 10, 2023November 13, 2023

The Hayabusa2 space mission by the Japan Aerospace Exploration Agency (JAXA) returned home with samples of the asteroid Ryugu that orbits the Sun between Earth and Mars.

The first public display of a sample from asteroid Bennu Credit: (NASA/Keegan Barber)

Astrochemistry, Astrogeology, Comets and Asteroids, Meteorites & Asteroids, Missions & Hardware, Press Release

National Museum of Natural History Unveils Display of Asteroid Bennu Sample

by Keith CowingNovember 3, 2023

The first public display of a sample from asteroid Bennu is seen, Friday, Nov. 3, 2023, at the Smithsonian’s National Museum of Natural History in Washington.

Schematic diagram of the idealised planetary system considered in this work with equally spaced planets (brown circles, semi-major axis ai) scattering comets (small dark blue circles) from the snow-line. The blue region represents the volatile-rich region of the disc where comets occur, and the green region represents the habitable zone. Low velocity cometary impacts onto habitable planets will follow the lower arrows, which sketch the dynamically cold scattering between adjacent planets. The dynamically hot scattering as shown by the upper arrows, will result in high velocity impacts. -- astro-ph.EP

Astrochemistry, Astrogeology, Biochemistry & Organic Chemistry, Comets and Asteroids, Exoplanets, -moons, -comets, Meteorites & Asteroids, Panspermia, Status Report

Can Comets Deliver Prebiotic Molecules To Rocky Exoplanets?

by Keith CowingOctober 23, 2023October 20, 2023

In this work we consider the potential of cometary impacts to deliver complex organic molecules and the prebiotic building blocks required for life to rocky exoplanets. Numerical experiments have demonstrated […]