trans-Neptunian objects Archives - Astrobiology

[TOP] Example observations of (2060) Chiron for survey/telescopes (left) ATLAS, (middle) ZTF, and (right) LCO/LOOK. [BOTTOM] Example observations of 103P/Hartley 2 for survey/telescopes (left) ATLAS, (middle) ZTF, and (right) LCO/LOOK. -- astro-ph.EP

Comets and Asteroids

Multi-year Ground-Based Survey Photometry of Active Comet 103P/Hartley 2 and Centaur (2060) Chiron: A Tale of Two Comets in the Pre-LSST Era

by Keith CowingJuly 5, 2026July 5, 2026

[astro-ph.EP] Comets and Centaurs trace the evolution of trans-Neptunian objects (TNOs) into the inner solar system.

Protoplanetary disk images (top row) and scattered-/transmitted-light spectra (bottom-left and bottom-middle) obtained from the radiative-transfer simulations, together with the crystallinity dependence of their Fresnel-feature heights (bottom-right). For the edge-on case, the Fresnel-feature height is measured in absolute value of feature depth. Alt text: Theoretical images, spectra, and Fresnel feature height of the protoplanetary disks. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biosignatures & Paleobiology, Imaging & Spectroscopy, Interstellar, Status Report

Constraints On The Crystallinity Of Water Ice In Planet-forming Disks From Infrared Scattered-Light Spectra

by Keith CowingMay 23, 2026May 23, 2026

The crystallinity of water ice not only records the thermal history experienced by an astronomical body, but also affects the composition of forming planets by controlling the trapping of volatile […]

Three station light curves of 2002 XV93’s stellar occultation on 10 January 2024. The flux points (points with error bars) observed at Kyoto (a), Kiso (b) and Fukushima stations (c) overlaid with the synthetic light curves (red lines, assuming a pure CH4 atmosphere and a best-fit surface pressure of 124 nanobars) are shown as a function of time. In panel c, the gray points are the flux points for the individual exposures, and the black points are those binned by a factor of 8. The vertical arrow represents the closest approach time to the shadow edge at Fukushima, at 13:12:50.818 UT. -- astro-ph.EP

Astrochemistry, Astronomy & Telescopes, Atmospheres, Climate, Weather, Exoplanets, -moons, -comets, Icy Worlds, Imaging & Spectroscopy, Pluto, Status Report

The First Detection Of An Atmosphere On A Trans-Neptunian Object Beyond Pluto

by Keith CowingMay 8, 2026May 8, 2026

Trans-Neptunian objects (TNOs) in the outer Solar System are predominantly small, icy worlds long presumed to be atmosphereless except for the largest bodies.

Effect of flyby. (a) The pre-flyby colour gradient in the simulated disc is depicted by a false colour scheme representing very red to blue-grey TNOs. The same colour scheme is used throughout the paper. (b) Simulation snapshot of the flyby 128 years after periastron passage. The perturber star approached from the bottom right and already left the shown area. Disc matter is transported inwards and outwards along the spiral arms, with a fraction of the test particles injected into the planet region. Only the particles remaining bound to the Sun are shown. -- astro-ph.EP

Astrochemistry, Astrogeology, Comets and Asteroids, Imaging & Spectroscopy, Press Release, Stellar Cartography

TNO Colours Provide New Evidence For A Past Close Flyby Of Another Star To The Solar System

by Keith CowingJuly 13, 2025July 13, 2025

Thousands of small bodies, known as trans-Neptunian objects (TNOs), orbit the Sun beyond Neptune. TNOs are remnants of the planets’ formation from a disc of gas and dust, so it […]

Images of the trans-Neptunian objects (TNOs) Pluto [left] and Arrokoth [right], the primary flyby targets of NASA’s New Horizons spacecraft in 2015 and 2019. NASA’s James Webb Space Telescope is capable of obtaining observations for in-depth studies of a wide range of TNOs that both complement, and go beyond what was learned by New Horizons. (Image credits: NASA/SwRI/JHU-APL)

Astrochemistry, Astrogeology, Astronomy & Telescopes, Biochemistry & Organic Chemistry, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Comets and Asteroids, Cryobiology, Icy Worlds, Imaging & Spectroscopy, Pluto, Status Report

Webb Reveals The Ancient Surfaces of Trans-Neptunian Objects

by Keith CowingFebruary 13, 2025February 13, 2025

Trans-Neptunian objects (TNOs) are icy bodies ranging in size from Pluto and Eris (dwarf planets with diameters of about 1,500 miles) down to tens of miles (Arrokoth) and even smaller. […]

Time evolution (from left to right) of small grains around Makemake under the influence of solar radiation pressure. -- astro-ph.EP

Astrochemistry, Astrogeology, Comets and Asteroids, Icy Worlds, Imaging & Spectroscopy, Status Report

Prominent Mid-infrared Excess Of The Dwarf Planet (136472) Makemake Discovered by JWST/MIRI Indicates Ongoing Activity

by Keith CowingOctober 31, 2024October 31, 2024

We report on the discovery of a very prominent mid-infrared (18-25 um) excess associated with the trans-Neptunian dwarf planet (136472) Makemake.

Optical reflectance spectra of 2004 GV9. Panel A: Here we compare our new GMOS reflectance spectra of 2004 GV9 both to each other and to coarse spectra derived from published single-epoch photometry (Rabinowitz et al. 2008; DeMeo et al. 2009; Fraser et al. 2015; Tegler et al. 2016). Hollow points in the GMOS spectra are either affected by incomplete background subtraction, telluric band residuals, proximity to the GMOS chip gaps, or a combination of these effects. All datasets are scaled to unit reflectance at 0.625 µm. We present all spectra calibrated with HD 124523 overlaid for direct comparison, and also offset for clarity. All offset spectra are offset vertically in increments of +0.2. Panel B: Here we show our 2004 GV9 spectra following division by a line fitted to them across their full wavelength coverage. Spectra from each epoch are offset vertically for clarity in increments of +0.1. Only spectra calibrated with HD 124523 are shown. Points affected by residuals of telluric absorption or imperfect background subtraction have been omitted. -- astro-ph.EP

Astrochemistry, Astrogeology, Astronomy & Telescopes, Comets and Asteroids, Imaging & Spectroscopy, Meteorites & Asteroids, Status Report

Hunting for Hydrated Minerals on Trans-Neptunian Objects

by Keith CowingDecember 20, 2023December 20, 2023

We present new optical reflectance spectra of three potentially silicate-rich Trans-Neptunian Objects (TNOs). These spectra were obtained with the aim of confirming past hints and detections of 0.7 micron absorption […]

Earth-like Planet in the Distant Kuiper Belt

Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Status Report

Is There an Earth-like Planet in the Distant Kuiper Belt?

by Keith CowingAugust 30, 2023August 30, 2023

The orbits of trans-Neptunian objects (TNOs) can indicate the existence of an undiscovered planet in the outer solar system. Here, we used N-body computer simulations to investigate the effects of […]