Posted on 01/07/2025 5:35:38 AM PST by Red Badger
An artistic representation of Chiron’s nucleus surrounded by debris and a coma of dust and gas. Credit: William Gonzalez Sierra
UCF researchers utilized the James Webb Space Telescope to uncover unique characteristics of (2060) Chiron, a distant “centaur” that exhibits traits of both a comet and an asteroid. These findings provide valuable insights into the origins of our Solar System.
Although our Solar System is billions of years old, we’ve only recently gained deeper insight into one of its most dynamic and intriguing members: (2060) Chiron.
Chiron belongs to a group of celestial objects known as “Centaurs.” These objects orbit the Sun between Jupiter and Neptune and are aptly named after the mythological Centaur—a hybrid creature—because they exhibit traits of both asteroids and comets.
In a groundbreaking study using the James Webb Space Telescope, scientists from the University of Central Florida’s Florida Space Institute (FSI) discovered that Chiron’s surface chemistry is distinct from other Centaurs. For the first time, they identified carbon dioxide and carbon monoxide ices on its surface, along with carbon dioxide and methane gases in its coma—the diffuse cloud of dust and gas surrounding the object.
The researchers’ results were recently published in the journal Astronomy & Astrophysics.
Building on Previous Discoveries
UCF FSI Associate Scientist Noemí Pinilla-Alonso, who now works at the University of Oviedo in Spain, and Assistant Scientist Charles Schambeau led the research. The new findings build upon prior discoveries from Pinilla-Alonso and colleagues that detected carbon monoxide and carbon dioxide ice on trans-Neptunian objects (TNOs) for the first time earlier this year.
Those observations, paired with ones of Chiron, are creating foundational knowledge for understanding the creation of our Solar System, as these objects have largely remained unchanged since the Solar System was formed, Pinilla-Alonso says.
2060 Chiron Chemical Composition. The colored bands highlight the different ices such as water ice, carbon oxides and light hydrocarbons. Inset: Detail of 2060 Chiron reflectance highlighting the fluorescence of methane gas together with absorptions of ethane and propane ices. Credit: William Gonzalez Sierra
“All the small bodies in the Solar System talk to us about how it was back in time, which is a period of time we can’t really observe anymore,” she says. “But active centaurs tell us much more. They are undergoing transformation driven by solar heating and they provide a unique opportunity to learn about the surface and subsurface layers.”
Since Chiron possesses characteristics of both an asteroid and a comet, it makes it rich for studying many processes that could assist in understanding them, she says.
“What is unique about Chiron is that we can observe both the surface, where most of the ices can be found, and the coma, where we see gases that are originating from the surface or just below it,” Pinilla-Alonso says. “TNOs don’t have this kind of activity because they’re too far and too cold. Asteroids don’t have this kind of activity because they don’t have ice on them. Comets, on the other hand, show activity like centaurs, but they are typically observed closer to the Sun, and their comas are so thick that they complicate the interpretations of observations of the ices on the surface. Discovering which gases are part of the coma and their different relationships with the ices on the surface help us learn the physical and chemical properties, such as the thickness and the porosity of the ice layer, its composition, and how irradiation is affecting it.”
The discovery of these ices and gases on an object as distant as Chiron – observed near its farthest point from the Sun – is exciting because it could help contextualize other centaurs and provide insight into the earliest era of our Solar System, Schambeau says.
Artistic representation of an active centaur like Chiron. The different colors in the coma indicate varying compositions of gas, ice, and dust. Credit: William Gonzalez Sierra
“These results are like nothing we’ve seen before,” he says. “Detecting gas comae around objects as far away from the Sun as Chiron is very challenging, but JWST has made it accessible. These detections enhance our understanding of Chiron’s interior composition and how that material produces the unique behaviors as we observe Chiron.”
Schambeau specializes in studying centaurs, comets, and other space objects. He analyzed the methane gas coma and determined that the outflowing gas detected was consistent with it being sourced from a surface area that was exposed to the most heating from the Sun.
Chiron: An “Oddball” Among Centaurs
Chiron, first discovered in 1977, is characterized much better than most centaurs and comparatively is unique, Schambeau says. The newly analyzed information helps scientists better understand the thermophysical process going on in Chiron that produces methane gas, he says.
“It’s an oddball when compared to the majority of other Centaurs,” Schambeau says. “It has periods where it behaves like a comet, it has rings of material around it, and potentially a debris field of small dust or rocky material orbiting around it. So, many questions arise about Chiron’s properties that allow these unique behaviors.”
The researchers concluded that the coexistence of the molecules in various states adds another layer of intrigue for studying comets and centaurs. The study also highlighted the presence of irradiated byproducts of methane, carbon monoxide, and carbon dioxide that will require further research and could help scientists further reveal the unique processes producing Chiron’s surface composition.
Chiron originated from the TNO region and has traveled around our Solar System since its creation, says Pinilla-Alonso. The orbits of Chiron and many other large non-planetary objects occasionally experience close encounters with one of the giant planets where the gravitational pull from the planet changes the smaller object’s orbit, taking them all over our Solar System and exposing them to many different environments, she says.
VIDEO AT LINK...............
“We know it has been ejected from the TNO population and is only now transiting through the region of the giant planets, where it will not stay for too long,” Pinilla-Alonso says. “After about 1 million years, centaurs like Chiron typically are ejected from the giant planets region, where they may end their lives as Jupiter Family comets or they may return to the TNOs region.”
Pinilla-Alonso notes that the JWST’s spectra showed for the first time Chiron’s plethora of ices with different volatilities and their formation processes, she says.
Some of these ices, such as methane, carbon dioxide, and water ice, may be primordial components of Chiron inherited from the pre-solar nebula. Others, such as acetylene, propane, ethane, and carbon oxide, could have formed on the surface because of reduction and oxidation processes, she says.
“Based on our new JWST data, I’m not so sure we have a standard centaur,” Pinilla-Alonso says. “Every active centaur that we are observing with JWST shows some peculiarity. But they cannot be all outliers. There must be something that explains why they appear to all behave differently or something that is common between them all that we cannot yet see.”
The analysis of Chiron’s gases and ices opens new frontiers and opportunities for exciting research, she says.
“We’re going to follow up with Chiron,” Pinilla-Alonso says. “It will come closer to us, and if we can study it at nearer distances and get better reads on the quantities and nature of the ices, silicates, and organics, we will be able to better understand how seasonal insolation variations and different illumination patterns can affect its behavior and its ice reservoir.”
Reference:
“Unveiling the ice and gas nature of active centaur (2060) Chiron using the James Webb Space Telescope”
by N. Pinilla-Alonso, J. Licandro, R. Brunetto, E. Henault, C. Schambeau, A. Guilbert-Lepoutre, J. Stansberry, I. Wong, J. I. Lunine, B. J. Holler, J. Emery, S. Protopapa, J. Cook, H. B. Hammel, G. L. Villanueva, S. N. Milam, D. Cruikshank and A. C. de Souza-Feliciano, 18 December 2024, Astronomy & Astrophysics.
DOI: 10.1051/0004-6361/202450124
Ping!..............
Wow, didn't know that such a collection even existed.
Way to go to the International Astronomical Union (IAU).
That’s a lot of rocks!......................
Prediction: someday we’ll discover primordial RNA components on these ancient objects.
In Act 1 Scene 5 of Shakespeare’s play, Hamlet,
Hamlet says to his friend:
“There are more things in Heaven and Earth, Horatio,
than are dreamt of in your philosophy.”
“…its coma—the diffuse cloud of dust and gas surrounding the object.”
So, its atmosphere.
“,,,back in time, which is a period of time we can’t really observe anymore,”
Astute observation.
“…these objects have largely remained unchanged since the Solar System was formed,…”
They know this how? (“...back in time, which is a period of time we can’t really observe anymore). But: “They are undergoing transformation driven by solar heating…”
They’ve “largely remained unchanged since the Solar System was formed” but are just now “undergoing transformation driven by solar heating”?
Trust the Science.
Maybe being snowbound is affecting my attitude.
[Chiron: An “Oddball” Among Centaurs]
So, is this “Centaur” a “Unicorn”?
I didn’t, either. I saved a link to that page for future reference. This Chiron object would be a great target for a space probe.
I’m curious how these can be ‘unchagned’, yet are off-gassing and have comas.
Is there a presumption that they are regathering that offgassed material, or how is it being replenished?
Missing piece of the equation here.
Selections from the keywords, sorted:
That’s Superyeti.
He’s like Superman only yeti.
carbon dioxide and methane gases in its coma
—
Obvious signs of life.
Dead starship slowly venting the last of its gases.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.
