Interstellar comet 3I/ATLAS may be developing a blueish hue after undergoing a rapid and unexpected brightening event while hidden behind the sun, new observations reveal. This is the third time that experts have noted a potential change to the comet's color — but, so far, none of them have stuck.
3I/ATLAS, the third-known interstellar object to visit our solar system, was spotted shooting toward the sun at more than 130,000 mph (210,000 km/h) in early July. The comet is potentially the oldest of its kind ever seen and was likely ejected from its home star system, somewhere in the Milky Way's frontier, more than 7 billion years ago. Since then, it has sailed through interstellar space, before making its current rendezvous with our solar system.
