New research from the James Webb Space Telescope (JWST) has revealed some fascinating details about comet 3I/ATLAS. This comet, on its epic journey through the Milky Way, has absorbed a staggering amount of cosmic radiation over billions of years, leading to significant changes in its structure.
As it travels through interstellar space, 3I/ATLAS has developed a thick irradiated crust. This crust doesn’t resemble the original material from its home star system anymore. The study suggests that the comet’s “extreme” carbon dioxide (CO2) levels are a result of this cosmic radiation, which has also altered its ice composition down to about 15 to 20 meters deep.
Galactic cosmic rays, made up of high-energy particles, play a crucial role in this transformation. They strike carbon monoxide (CO) in space, converting it to carbon dioxide (CO2). While Earth is shielded from most of this radiation by the heliosphere, 3I/ATLAS has been exposed to it for much of its long life.
Romain Maggiolo, a research scientist involved in the study, explained that these slow but powerful effects accumulate over billions of years. As a result, comet 3I/ATLAS may represent material altered by cosmic radiation rather than the pristine material from where it originally formed.
As it approaches the sun, the comet heats up. This heat causes gases to escape from its surface. Observations suggest that these gases mainly come from the outer irradiated crust. It remains to be seen if any untouched material from its original formation will be exposed after it passes closest to the sun, a point known as perihelion.
Interestingly, since its discovery in July, this comet has been traveling through our solar system at speeds over 130,000 mph. It might even be one of the oldest comets ever studied, potentially 3 billion years older than our solar system.
Researchers are excited to analyze changes in the comet’s composition before and after perihelion. By comparing these observations, scientists hope to uncover insights about its original makeup.
This new understanding not only shifts how we study interstellar objects but also highlights the intricate tales written in the cosmos by radiation and time. With ongoing research, comet 3I/ATLAS continues to be a source of wonder, revealing the vast history and transformations of celestial bodies in our universe.
For further reading, you can check out the original findings from the study on arXiv.
