Interstellar Comet 3I/ATLAS Traced to Milky Way's Thick Disk, Suggesting Ancient Origins
Astronomers have traced the trajectory of interstellar comet 3I/ATLAS, indicating it originated from the Milky Way's thick disk, suggesting it may be over 7 billion years old.
Astronomers have identified interstellar comet 3I/ATLAS as originating from the Milky Way's thick disk, a region populated by ancient stars. This discovery suggests that 3I/ATLAS may be over 7 billion years old, predating our solar system by approximately 3 billion years.
Discovered on July 1, 2025, 3I/ATLAS is the third confirmed interstellar object to pass through our solar system, following 'Oumuamua in 2017 and 2I/Borisov in 2019. The comet is estimated to be between 1,444 feet (440 meters) and 3.5 miles (5.6 kilometers) in diameter.
Researchers utilized data from the European Space Agency's Gaia mission to trace the comet's trajectory over the past 10 million years. Their analysis revealed no significant stellar encounters that could account for its current path, reinforcing the hypothesis of its ancient origin.
The European Space Agency's ExoMars Trace Gas Orbiter recently captured images of 3I/ATLAS as it passed near Mars, providing valuable data on its composition and behavior.
Further observations are planned as 3I/ATLAS approaches the Sun in late October 2025 and passes near Jupiter in March 2026. These studies aim to enhance our understanding of interstellar objects and the early history of the Milky Way.