In recent days, the brightness of comet 3I/ATLAS has notably decreased by over one-third, even as the object continues its rapid approach towards Earth. The stellar magnitude increased from its previous 10.1 to 10.6, effectively indicating a drop in brightness to approximately 63% of the level observed six days ago. Despite the reduction in distance from Earth by ten million kilometers (6 million miles), the comet is fading due to its gradual movement away from the Sun, whose reflected light enhances its visibility. Internal processes, especially changes in the albedo of the nucleus (a low capacity to reflect sunlight), cannot be ruled out.
Even amidst the decreased brightness, 3I/ATLAS remains high in the rankings, holding fourth place among almost one hundred currently observed comets. The lead is maintained by C/2025 A6 Lemmon, whose luminosity has decreased nearly tenfold over the month but remains high. Fresh images of 3I/ATLAS reveal an unusual fluffy tail structure and noticeable dynamics, ensuring the object continues to intrigue not only scientists but also owners of semi-professional tools.
A major question in the coming weeks is whether NASA will engage the Hubble and James Webb telescopes for new observations. Both instruments have previously captured 3I/ATLAS but from a significantly greater distance from the Sun. The current orbital configuration will allow the tools to be safely directed at the object within two to three weeks; however, no specific comments have been forthcoming from the agency so far.
Previously, we reported that as 3I/ATLAS moves further from the Sun, a rare dust antitail continues to manifest distinctly. The conjunction of factors with the seasonal interplay of solar influences makes scientists anticipate an extraordinary celestial phenomenon. Many are eager to see if this comet will provide new insights into the conditions of the early solar system, prompting increased interest and anticipation among amateur astronomers, as well as a reevaluation of theoretical models of comet behavior.
