Interstellar comet keeps its distance as it makes its closest approach to Earth

By: Marcia Dunn, The Associated Press Posted: 7:02 AM CST Monday, Dec. 15, 2025

CAPE CANAVERAL, Fla. (AP) — A stray comet from another star swings past Earth this week in one last hurrah before racing back toward interstellar space.

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CAPE CANAVERAL, Fla. (AP) — A stray comet from another star swings past Earth this week in one last hurrah before racing back toward interstellar space.

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This article was published 15/12/2025 (306 days ago), so information in it may no longer be current.

CAPE CANAVERAL, Fla. (AP) — A stray comet from another star swings past Earth this week in one last hurrah before racing back toward interstellar space.

Discovered over the summer, the comet known as 3I/Atlas will pass within 167 million miles (269 million kilometers) of our planet on Friday, the closest it gets on its grand tour of the solar system.

NASA continues to aim its space telescopes at the visiting ice ball, estimated to be between 1,444 feet (440 meters) and 3.5 miles (5.6 kilometers) in size. But it’s fading as it exits, so now’s the time for backyard astronomers to catch it in the night sky with their telescopes.

This image, provided by NASA, shows the interstellar comet 3I/Atlas captured by the Hubble Space Telescope on Nov. 30, 2025, about 178 million miles (286 million kilometers) from Earth. (NASA, ESA, STScI, D. Jewitt (UCLA), M.-T. Hui (Shanghai Astronomical Observatory), J. DePasquale (STScI) via AP)

The comet will come much closer to Jupiter in March, zipping within 33 million miles (53 million kilometers). It will be the mid-2030s before it reaches interstellar space, never to return, said Paul Chodas, director of NASA’s Center for Near Earth Object Studies.

It’s the third known interstellar object to cut through our solar system. Interstellar comets like 3I/Atlas originate in star systems elsewhere in the Milky Way, while home-grown comets like Halley’s hail from the icy fringes of our solar system.

A telescope in Hawaii discovered the first confirmed interstellar visitor in 2017. Two years later, an interstellar comet was spotted by a Crimean amateur astronomer. NASA’s sky-surveying Atlas telescope in Chile spotted comet 3I/Atlas in July while prowling for potentially dangerous asteroids.

Scientists believe the latest interloping comet, also harmless, may have originated in a star system much older than ours, making it a tantalizing target.

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The Associated Press Health and Science Department receives support from the Howard Hughes Medical Institute’s Department of Science Education and the Robert Wood Johnson Foundation. The AP is solely responsible for all content.