New interstellar comet will keep a safe distance from Earth, NASA says

This diagram provided by NASA/JPL-Caltech shows the trajectory of interstellar comet 3I/ATLAS as it passes through the solar system. (NASA/JPL-Caltech via AP)

CAPE CANAVERAL, Fla. — NASA has discovered an interstellar comet that’s wandered into our backyard.

The space agency spotted the quick-moving object with the Atlas telescope in Chile earlier this week, and confirmed it was a comet from another star system.

It’s officially the third known interstellar object to pass through our solar system and poses no threat to Earth.

“These things take millions of years to go from one stellar neighbourhood to another, so this thing has likely been traveling through space for hundreds of millions of years, even billions of years,” Paul Chodas, director of NASA’s Center for Near Earth Object Studies, said Thursday. “We don’t know, and so we can’t predict which star it came from.”

The newest visitor is 416 million miles (670 million kilometres) from the sun, out near Jupiter, and heading this way at a blistering 37 miles (59 kilometres) per second.

NASA said the comet will make its closest approach to the sun in late October, scooting between the orbits of Mars and Earth -- but closer to the red planet than us at a safe 150 million miles (240 million kilometres) away.

Astronomers around the world are monitoring the icy snowball that’s been officially designated as 3I/Atlas to determine its size and shape. Chodas told The Associated Press that there have been more than 100 observations since its discovery on July 1, with preliminary reports of a tail and a cloud of gas and dust around the comet’s nucleus.

The comet should be visible by telescope through September, before it gets too close to the sun, and reappear in December on the other side of the sun.

Based on its brightness, the comet appears to be bigger than the first two interstellar interlopers, possibly several miles (tens of kilometers) across, Chodas said. It’s coming in faster, too, from a different direction, and while its home star is unknown, scientists suspect it was closer to the center of our Milky Way galaxy.

The first interstellar visitor observed from Earth was Oumuamua, Hawaiian for scout, in honor of the observatory in Hawaii that discovered it in 2017. Classified at first as an asteroid, the elongated Oumuamua has since showed signs of being a comet.

The second object confirmed to have strayed from another star system into our own -- 21/Borisov -- was discovered in 2019 by a Crimean amateur astronomer with that name. It, too, is believed to be a comet.

“We’ve been expecting to see interstellar objects for decades, frankly, and finally we’re seeing them,” Chodas said. “A visitor from another solar system, even though it’s natural -- it’s not artificial, don’t get excited because some people do ... It’s just very exciting.”

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Marcia Dunn, The Associated Press

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