What can a newly discovered interstellar comet teach scientists about solar system formation and evolution? This is what a recent study presented at the National Astronomy Meeting 2025 hopes to address as a team of scientists investigated the 3I/ATLAS comet, which is designated as the third interstellar object to visit our solar system, is potentially the farthest that has traveled to reach us, and is estimated to be approximately seven billion years old, which is three billion years older than our solar system. Therefore, this study has the potential to help scientists better understand the formation and evolution of planets and solar systems throughout the universe.
Discovered on July 1, 2025, from the ATLAS survey telescope in Chile, 3I/ATLAS is appropriately named for being the third interstellar object and its discovery location. Like traditional comets, 3I/ATLAS heats up as it comes closer to the Sun, resulting in outgassing and discharging material, enabling scientists to study its composition. Additionally, scientists hypothesize that 3I/ATLAS’ path indicates it originated from a region of the Milky Way that exists above and below the plane where our solar system exists, and is comprised of stars much older than our Sun. As a result, scientists estimate that 3I/ATLAS is approximately three billion years older than our solar system.
Illustration depicting the paths of the Sun (yellow) and 3I/ATLAS (red). (Credit: M. Hopkins/Ĺtautahi-Oxford team. Base map: ESA/Gaia/DPAC, Stefan Payne-Wardenaar, CC-BY-SA 4.0)
"This is an object from a part of the galaxy we've never seen up close before," said Dr. Chris Lintott, who is a Professor of Astrophysics at the University of Oxford and a co-author on the study. "We think there's a two-thirds chance this comet is older than the solar system, and that it's been drifting through interstellar space ever since."
3I/ATLAS is estimated to be visible from amateur telescopes during late 2025 and early 2026.
What new discoveries about 3I/ATLAS will researchers make in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Royal Astronomical Society, EurekAlert!
