A groundbreaking discovery in our Solar System: a hybrid of a comet and an asteroid unlike any other known objects.

Astronomers using the Webb Space Telescope have discovered that the centaur (2060) Chiron is a very unusual object orbiting the Sun between Jupiter and Neptune. It turns out that it has a chemical composition never before seen in other small bodies in the outer Solar System. This new finding could alter our understanding of both centaurs and the early history of the Solar System. The research has been published in the journal Astronomy & Astrophysics, reports Space.

Centaurs are small bodies in the Solar System that exhibit characteristics of both asteroids and comets. Currently, about a thousand centaurs are known to exist, but (2060) Chiron, which is 218 km wide, was the first such object discovered in 1977.

As centaurs approach the Sun, they heat up, which can lead to the sublimation of some of the ices they contain. This process creates a gas cloud around the centaurs, similar to a comet's coma. According to scientists, (2060) Chiron stands out among other small bodies in the outer Solar System because it sometimes behaves like a comet and has rings of dust.

New observations have shown that the chemical composition of the ices on the surface of centaur (2060) Chiron is completely different from that of other centaurs. Although none of the ices themselves are particularly unusual, their combination on this centaur surprised scientists.

According to the study's authors, the surface of centaur (2060) Chiron was found to contain ice made of carbon monoxide and carbon dioxide, as well as carbon dioxide and methane in its coma. The exposure of these ices to solar radiation stimulates chemical reactions that produce organic byproducts, such as acetylene, ethane, propane, and various carbon oxides, all of which have been detected as ices on the surface of the centaur.

It is believed that centaurs and trans-Neptunian objects (small bodies beyond Neptune's orbit) have remained in their primordial state since the formation of the Solar System 4.5 billion years ago. Thus, they serve as "time capsules" that provide insight into how and from what the Solar System was formed, where certain objects originated in the protoplanetary disk, and whether they have moved elsewhere. However, such an active centaur as (2060) Chiron offers greater opportunities to obtain information about the early history of the Solar System, scientists say.

(2060) Chiron has a 50-year elliptical orbit. Three years ago, it was at its farthest point from the Sun, and now it has begun to approach our star. As the centaur gets closer to the Sun, it will become brighter and more active, allowing for more precise observations of the nature of its ices, its organic chemistry, and how solar radiation may affect its frozen surface.