Comet 3I/ATLAS, recognized as the third confirmed interstellar object, is set to reach its perihelion on October 29. At this point, it will be approximately 204 million kilometers from the Sun, or 1.36 astronomical units. The comet was first observed in July 2025, and its origin lies beyond our Solar System.
Astronomers will monitor the perihelion event at 8:47 AM Brasilia time. The distance from the Sun is significant, as it reduces the likelihood of the comet”s complete fragmentation. As the comet approaches the Sun, the increase in solar heat will trigger the sublimation of its icy components, leading to the formation of a coma and a tail.
The discovery of Comet 3I/ATLAS was made possible through images captured by the CCOR-1 coronagraph aboard the GOES-19 satellite. An amateur astronomer played a pivotal role in processing daily data from behind the Sun. Analysis indicates that this comet”s origins can be traced back to an unidentified star within the Milky Way. The chemical makeup of the comet provides valuable insights into how planets form in distant star systems.
As the comet heats up, ice in its nucleus converts into gas, releasing dust that creates structures visible from Earth. The safe distance, greater than that of Mercury”s orbit, minimizes potential risks. While some minor cracks may develop in fragile areas of the comet, its overall structure is expected to remain stable, as studies have confirmed its integrity post-perihelion.
Following its closest approach to the Sun, Comet 3I/ATLAS will gradually move away, becoming visible again in the early morning sky on November 3. It will reside in the constellation of Virgo until November 17, rising about three degrees each day.
The Earth will pass closest to the comet on December 19, at a distance of 269 million kilometers. In March 2026, Jupiter will enter its orbit at a distance of 54 million kilometers, slightly altering the comet”s trajectory. Brightness will diminish until late March 2026, but telescopes will capture images of the comet just before dawn, appearing nine degrees above the eastern horizon.
Animations are being generated to simulate the comet”s journey through the Solar System, with updated orbital parameters provided by the Jet Propulsion Laboratory (JPL). Observatories in Namibia have recorded jets of ice from the comet, and established platforms are ensuring accurate predictions of its path. Current parameters indicate a hyperbolic orbit, with the comet traveling at a velocity that exceeds the solar escape speed.
