Cosmic Radiation: Billions of Years of Exposure

KOMPAS.com – Interstellar Comet 3I/ATLAS, a newcomer from outside the Solar System, now reveals the secrets of its billion-year journey.

Recent observations using the James Webb Space Telescope (JWST) show that the comet has a thick, cosmically irradiated crust, making its composition no longer reflective of material from its native star system.

This research suggests that 3I/ATLAS has absorbed so many galactic cosmic rays during its interstellar journey across the Milky Way that it has developed a deep irradiated crust.

This crust is what covers the original material.

Also read: What happened to Comet 3I/ATLAS when it boiled at the closest point to the sun?

Extreme Carbon Dioxide Due to Cosmic Rays

Using JWST data and computer simulations, the researchers concluded that the comet’s high levels of carbon dioxide (CO2) came from space radiation absorbed during its estimated 7 billion year lifespan.

Quoted Live Science, Galactic cosmic rays—a type of space radiation consisting of high-energy particles from outside the Solar System—hit carbon monoxide (CO) in space, turning it into carbon dioxide (CO2).

Within our Solar System, the heliosphere (a bubble of radiation emitted by the Sun) protects Earth and its neighbors from most of this cosmic radiation.

However, in interstellar space, where 3I/ATLAS has spent most of its life, no such protection exists.

Romain Maggiolo, lead author of the study and research scientist at the Royal Belgian Institute for Space Aeronomy, explained the long-term impact.

“It was very slow, but over billions of years, it was a very powerful effect,” Maggiolo said.

The study authors concluded that over billions of years, cosmic rays have significantly changed the physical state of comet 3I/ATLAS’s ice, to a depth of about 15 to 20 meters.

Also read: Rare photo from the sky: Comet Lemmon appears to be entangled in a meteor

Shifting Paradigms for the Study of Interstellar Objects

This finding, which the researchers describe as a “paradigm shift” in the study of interstellar objects, implies that objects like 3I/ATLAS are composed largely of material that has been processed by galactic cosmic rays, rather than pure material that is a representation of the environment in which they formed.

In other words, comet 3I/ATLAS is now a product of its interstellar journey, not of its origin—at least on the outside.

3I/ATLAS, which is estimated to be around 3 billion years older than our Solar System which is 4.6 billion years old, is currently flying around the Sun.

The comet just reached perihelion (closest point to our star) on October 29.

Also read: There is a lot of talk about Comet 3I/ATLAS being called “Alien Technology”, Is it Really Dangerous for Earth? This is what BRIN said