Interstellar comet 3I/ATLAS expected to brighten in coming weeks
Images captured by the Gemini South telescope in Chile on Tuesday revealed a rapidly expanding tail and a brightening coma surrounding comet 3I/ATLAS, an object that originated outside the Solar System. The observations, processed by the International Gemini Observatory and its partners, show the comet's activity increasing as it approaches its perihelion, the point in its orbit closest to the Sun.
3I/ATLAS, the third confirmed interstellar visitor after 'Oumuamua in 2017 and comet Borisov in 2019, follows a hyperbolic trajectory that will carry it through the inner Solar System before it exits permanently. Astronomers estimate that the comet will reach a peak visual magnitude of around 6 to 7 in the next two to three weeks, making it potentially visible to binoculars under dark skies. The current brightness surge is attributed to solar heating causing volatile ices on the comet’s surface to sublimate, creating the observed tail that stretches several hundred thousand kilometers.
Scientists say the event offers a rare opportunity to study material that formed around another star. While detailed composition analysis will depend on follow‑up observations with larger facilities such as the Very Large Telescope and the upcoming James Webb Space Telescope, preliminary spectroscopy suggests the presence of water, carbon monoxide, and organic compounds similar to those found in Solar System comets. Experts note that such comparative studies can shed light on the diversity of planetary system formation across the galaxy.
International observatories have coordinated a monitoring campaign, with alerts issued to both professional and amateur astronomers. Local authorities in Chile and neighboring countries have advised sky‑watchers to avoid looking directly at the Sun while tracking the comet’s progress. The scientific community expects the data collected during this window to enhance models of interstellar object dynamics and to inform future mission concepts aimed at rendezvousing with similar bodies.
As 3I/ATLAS continues its journey, its visibility will gradually diminish after perihelion, and it will accelerate away from the Sun, eventually disappearing from view. Nonetheless, the brief encounter underscores the growing capability of ground‑based telescopes to detect and characterize objects that travel across interstellar space, expanding our understanding of the broader cosmos.
