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.
Latest about 3I/ATLAS
Comet 3I/ATLAS has been transformed by billions of years of space radiation, James Webb Space Telescope observations reveal
The interstellar comet 3I/ATLAS has a thick irradiated crust that no longer resembles its home star system, simulations and James Webb Space Telescope observations have found.
NASA spacecraft reveal interstellar comet 3I/ATLAS brightened rapidly as it swooped behind the sun
Interstellar comet 3I/ATLAS is briefly out of view as it travels around the sun this week, but researchers and amateur astronomers used spacecraft data to track its progress right up until perihelion.
Interstellar object 3I/ATLAS is about to get very active — Space photo of the week
The interstellar comet 3I/ATLAS is barreling toward its closest point to the sun as perihelion looms on Oct. 29. How different will it look when it reappears on the other side?
Two spacecraft will pass right through comet 3I/ATLAS' tail
Two ESA spacecraft, Hera and Europa Clipper, are poised to fly through the long tail of interstellar comet 3I/ATLAS, a new paper finds.
New images of interstellar object 3I/ATLAS show giant 'jet' shooting toward the sun
New telescope images show that the interstellar comet 3I/ATLAS is shooting a giant jet of gas and dust toward the sun. This is normal behavior for comets, an expert told Live Science.
Comet 3I/ATLAS is losing water 'like a fire hose' on full blast
Researchers have discovered that interstellar comet 3I/ATLAS has been shedding water, providing insights into the building blocks of life outside of our solar system and the evolution of interstellar comets.
'Closest view' yet of interstellar comet 3I/ATLAS captured by Mars orbiter
The European Space Agency's ExoMars orbiter has captured the closest view yet of the interstellar comet 3I/ATLAS. The images reveal the comet's bright coma but show no signs of a tail.
Interstellar comet 3I/ATLAS may come from the mysterious frontier of the early Milky Way, new study hints
The interstellar comet 3I/ATLAS does not come from our corner of the Milky Way, and may be a time capsule of the early galaxy, new research into its trajectory hints.
