“We don’t have any evidence for the gas coma changing colors.”
According to reporting by Space.com, scientists studying the interstellar visitor 3I/ATLAS have found no evidence that the comet’s appearance has undergone a dramatic colour change.
The comet—only the third known to originate beyond the solar system—was observed undergoing a “rapid brightening” as it approached the Sun. Some earlier media accounts suggested the dust surrounding 3I/ATLAS had shifted from red to blue.
These reports followed a pre-print study claiming the object was “distinctly bluer than the Sun” in comparison to earlier red-dust measurements.
However, Qicheng Zhang, a postdoctoral fellow at Lowell Observatory and co-author of the new study, said that “We don’t have any evidence for the gas coma changing colours.” He added: “Our result just showed that the gas coma is likely still around and contributing substantially to the overall brightness.”
The initial apparent “colour change” occurred only as the coma became visible and brightened — not as a later transformation. “As far as we know, the comet just ‘changed colour’ once when its gas coma first became visible/bright, and it’s still like that now (only brighter),” Zhang stated.
The findings help clarify the nature of this rare interstellar object and correct misunderstandings surrounding its behaviour.