The James Webb Space Telescope has discovered that a Centaur named 2060 Chiron is an oddity. The object is a small object located in the vast region between Jupiter and Neptune that orbits the sun, and it contains a mixture of ice and gas that makes it stand out from other objects in the distant outer solar system.
About 1,000 centaurs are known, but are 135 miles (218 kilometers) wide Chiron First discovered in 1977. Neptunebut later moved within the system after their orbits were perturbed by gravitational resonances with the ice giant. Because of their proximity to the sun, solar heating causes some of the ice to sublime, forming a gaseous halo or coma around the centaurs, something like comet.
Charles Schambeau of the University of Central Florida describes Chiron as an oddity among all other centaurs, even among trans-Neptunian objects (TNOs), which have their own interesting stories. “It can sometimes behave like a comet, with a ring of material around it and possibly a debris field composed of small dust or rocky material,” he said in a report. statement.
new James Webb Space Telescope JWST observations of Chiron, led by Chambeau and Noemi Pinilla-Alonso of the University of Oviedo in Spain, found that the composition of Chiron’s surface ice is unlike any other observed to date. Centaur is completely different. While there’s nothing particularly unusual about the ices themselves, their combination on Chiron is surprising.
The James Webb Space Telescope discovered carbon monoxide and carbon dioxide ice on its surface, and carbon dioxide and methane gas in Chiron’s thin coma. The presence and abundance of methane is consistent with material sublimating from ice on surface areas exposed to the greatest amount of solar heating. While the Sun’s temperature never exceeds -220 degrees Fahrenheit (-140 degrees Celsius), it’s still warm enough to cause these ices to sublime.
Additionally, the action of solar radiation on these ices stimulates chemical reactions that produce organic byproducts such as acetylene, ethane, propane, and various carbon oxides, all of which JWST found on Chiron’s surface.
“Discovering which gases are part of the coma and their different relationships with surface ice helps us understand physical and chemical properties, such as the thickness and porosity of the ice layer, its composition and how radiation affects it,” Pinilla said. – said Alonso.
Centauri and trans-Neptunian objects in general are considered primitive. They have remained untouched since their formation at the dawn of the universe 4.5 billion years ago. solar system. As such, they act like a time machine, giving us a glimpse into how and what the solar system is made of, where certain objects formed in the protoplanetary disk around the young Sun, and whether these objects migrated from that location.
Active centaurs like Chiron are especially valuable because they reveal so much more than their inert bodies.
“They are undergoing transformations driven by solar heating, and they provide unique opportunities to understand both the surface and subsurface layers,” said Pinilla-Alonso. “Chiron is unique in that we can observe both Coma can also be observed on the surface of the ice, where we can see gas originating from the surface or below the surface.”
Chiron’s 50-year elliptical orbit around the Sun passes through aphelion – its maximum distance from the Sun is 18.87 astronomical unit In 2021, it reaches perihelion (2.8 billion kilometers, or 1.75 billion miles). within, exactly within the orbit of the sun saturn. Over the next 20 years or so, Chiron will become brighter and more active, allowing more accurate observations of the abundance and properties of its ices, organic chemistry, and how solar radiation and sunlight affect its frozen surface. There is still much to learn.
“Based on our latest JWST data, I’m not sure we have a standard Centaur,” Pinilla-Alonso said. “Every active centaur we’ve observed with JWST exhibits some peculiarity. There must be something that explains why they behave differently, or there must be something in common between them that we haven’t seen yet.”
Alas, Chiron and all of its centaur brethren are in a transitional phase, and over the next few million years, its ultimate fate will be decided. Either the Jupiter family disperses it into the galaxy again and becomes a Jupiter family comet with an orbital period of less than 20 years, or it is thrown back into the solar system. Kuiper Beltdenied entry to the inner solar system by the gatekeeper Jupiter itself. It is impossible to say what its fate will be, but like an object named after a figure from Greek mythology, its fate will be in the hands of the gods.
The new JWST findings were published in the journal in December Astronomy and Astrophysics.