
3I/ATLAS is the third interstellar object ever discovered in our solar system. Telescope observations suggest it is a roughly 7-mile-wide (11 kilometers) comet zooming at more than 130,000 mph (210,000 km/h). Astronomers discovered it in early July as it emerged from beyond the orbit of Jupiter. An analysis of the comet’s composition and unusually flat, straight trajectory revealed that it did not originate within our cosmic neighborhood, and was likely ejected from a distant star system long before our sun ever formed.
The exotic comet has many peculiar properties, from its chemical composition to its large size. This has fuelled speculation that the comet is an alien spacecraft intentionally guided here. That’s almost certainly not the case, but it doesn’t mean that astronomers aren’t excited about studying it to better understand the conditions around other stars, the early Milky Way, and the frontier of interstellar space. Live Science will continue to follow the latest research as the comet reemerges from the far side of the sun in mid-November, becoming visible to Earth-based telescopes once again.

