In just a few days, Comet 3I/ATLAS will zoom in on its closest approach to the Sun. This third interstellar visitor is getting ready to show off, releasing gases and dust like it hasn’t done in eons. When we compare it to the previous two interstellar objects, it’s clear Comet 3I/ATLAS stands out.
Scientists David Jewitt and Jane Luu used the Nordic Optical Telescope in the Canary Islands to track changes in the comet from July to September. Their new paper, which is currently awaiting peer review, highlights its fascinating anti-tail and estimates the dust it sheds.
On October 29, the comet will be about 203 million kilometers (126 million miles) from the Sun. Astronomers found that even when it was 300 million kilometers away, it was ejecting about 180 kilograms (397 pounds) of dust every second. To put that in perspective, that’s like losing the weight of two kangaroos, or around 11 corgis, every second! In an hour, it amounts to the weight of six blue whales, and in 20.4 hours, it’s enough to match the mass of the Brooklyn Bridge.
While other comets are more active, 3I/ATLAS is notably lively compared to Comet 2I/Borisov, which released only 70 kilograms (154 pounds) of dust at a similar distance. Despite being part of the same cosmic family, their differences highlight the variety of these interstellar travelers.
This comet also boasts unique features. It’s faster, has a more eccentric orbit, and is possibly twice as old as our Solar System. Right now, it’s hiding behind the Sun, making it tough to observe. However, it will soon reappear, and more spacecraft will be on the lookout for it in the coming month.
As for how common these interstellar visitors might be, a recent study suggests they could be more frequent than previously thought. According to a 2022 survey, astronomers estimate around 30 interstellar comets might pass through our Solar System every year. This insight hints at a bustling cosmos, with comets like 3I/ATLAS contributing to our understanding of what exists beyond our solar neighborhood.
For the science enthusiasts out there, you can delve into more details in the full paper on arXiv.
