Interstellar comet 3I/ATLAS makes closest approach to Earth as an early Christmas gift
The Dec. 19 flyby of Comet 3I/ATLAS gave astronomers a rare chance to study only the third known interstellar object to pass through our solar system.
Scientists are tracking a rare interstellar comet, recently imaged by Hubble, as it passes safely through our solar system and remains visible for a few more months.
Astronomers and skywatchers had their chance to spot interstellar Comet 3I/ATLAS on Friday when it made its closest — but safely distant — flyby of Earth.
The comet has drawn global attention as only the third confirmed interstellar object observed passing through our solar system.
According to NASA, Comet 3I/ATLAS did not pose any threat to Earth during its pass. The object remained about 170 million miles from the planet when it made its distance flyby on Friday. Astronomers used the flyby to learn more about this mysterious visitor.
The Virtual Telescope Project will host a livestream at 11 p.m. EST on Friday to share views of the comet as it leaves Earth's neighborhood.
Since its discovery in July, NASA, the European Space Agency (ESA) and other international space organizations have used ground-based telescopes and spacecraft throughout the solar system to observe Comet ATLAS. NASA’s Mars rover even captured images of the object during its close approach to the Red Planet.
NASA’s Hubble Space Telescope reobserved interstellar comet 3I/ATLAS Nov. 30, with its Wide Field Camera 3 instrument. Image credit: NASA, ESA, STScI, D. Jewitt (UCLA), M.-T. Hui (Shanghai Astronomical Observatory). Image Processing: J. DePasquale (STScI)
More recently, NASA’s Hubble Space Telescope photographed the comet with its Wide Field Camera for the first time since July.
NASA's newest deep space explorer, the Europa Clipper spacecraft also observed the comet on Nov. 6 from about 102 million miles away with its ultraviolet spectrograph instrument.
Interstellar comet 3I/ATLAS is seen in this composite image captured on Nov. 6, 2025, by the Europa Ultraviolet Spectrograph instrument on NASA’s Europa Clipper spacecraft, from a distance of around 102 million miles away. (Image credit: NASA/JPL-Caltech/SWRI)
The National Science Foundation’s NOIRLab Gemini North telescope in Hawaii also collected new observations around Thanksgiving, revealing how the comet changed after its Oct. 30 close pass by the sun.
Earlier Gemini images showed Comet 3I/ATLAS with a reddish hue, but after swinging past the sun, it now appears with a faint greenish glow. According to NOIRLab, this shift is caused by light emitted from gases in the comet’s coma, including diatomic carbon, which glows green at certain wavelengths.
Comet 3I/ATLAS streaks across stars and galaxies in this image captured by the Gemini Multi-Object Spectrograph (GMOS) on Gemini North on Maunakea in Hawai‘i. This image is composed of exposures taken through four filters — blue, green, orange, and red. As exposures are taken, the comet remains fixed in the center of the telescope’s field of view. (Image credit: International Gemini Observatory/NOIRLab/NSF/AURA/B. Bolin Image Processing: J. Miller & M. Rodriguez (International Gemini Observatory/NSF NOIRLab), T.A. Rector (University of Alaska Anchorage/NSF NOIRLab), M. Zamani (NSF NOIRLab)
Despite speculation surrounding the comet’s origin, NASA and ESA experts say there is no evidence it is an alien or artificial object. Its color, speed and trajectory are all consistent with natural comet behavior, NASA said.
After its March flyby of Jupiter, Comet 3I/ATLAS will depart our solar system—leaving behind new clues about the mysteries of interstellar space.
Report a Typo
