The powerful Gemini North telescope in Hawai‘i has captured an image of 3I/ATLAS, the interstellar comet that's been discovered travelling through our Solar System.
Interstellar objects are bodies from deep space, and 3I/ATLAS is the third such object ever discovered in our own Solar System.
Gemini North has captured an image of 3I/ATLAS, and the observations could help scientists learn more about the comet's origin, orbit and composition.
Earlier the same week, we reported on how a group of smart telescope users teamed up to photograph 3I/ATLAS.
Why Gemini North's observations matter
A team of astronomers led by Karen Meech (Institute for Astronomy/University of Hawai‘i) used Gemini North to captured the image of 3I/ATLAS, which was first detected on 1 July 2025 by ATLAS (Asteroid Terrestrial-impact Last Alert System).
The telescope's Multi-Object Spectrograph (GMOS-N) gave astronomers a view of the comet’s compact coma, which is the cloud of gas and dust surrounding its icy nucleus.
"The sensitivity and scheduling agility of the International Gemini Observatory has provided critical early characterization of this interstellar wanderer," says Martin Still, NSF program director for the International Gemini Observatory.
"We look forward to a bounty of new data and insights as this object warms itself on sunlight before continuing its cold, dark journey between the stars."
One of many cosmic visitors?
Comet 3I/ATLAS is an 'interstellar object', meaning it originated outside of our Solar System.
Astronomers have only ever found three so far, the other two being 1I/ʻOumuamua in 2017 and comet 2I/Borisov in 2019.
It's thought many interstellar objects pass through our Solar System on a regular basis, but they're difficult to detect.
They range in size from tens of metres to a few kilometres wide, and are debris leftover from the formation of their host star’s planetary systems.
Much the same as asteroids are leftover debris from the formation of our own Solar System.
It's thought these celestial remnants are booted out of their orbit around a star by the gravity of nearby larger planets and passing stars.
As a result, interstellar visitors are invaluable specimens for learning about distant stars and planets, their formation and the chemistry involved.
What next for 3I/ATLAS?
Astronomers around the world are studying 3I/ATLAS as it passes through our Solar System.
There's still much to discover in terms of the comet's key characteristics, but it's thought 3I/ATLAS has a diameter of at most 20 kilometres (12 miles).
And it has a very eccentric orbit, which means its orbit is elongated or squashed like an egg shape, rather than a perfect circle.
3I/ATLAS has an eccentricity of 6.2, where an eccentricity of 0 is a perfect circle and an eccentricity of 0.999 is a stretched-out ellipse.
As of July 2025, 3I/ATLAS is within Jupiter’s orbit, 465 million kilometres (290 million miles) from Earth and 600 million kilometres (370 million miles) from the Sun.
It's thought 3I/ATLAS will get as close as 270 million kilometres (170 million miles) to Earth on 19 December 2025, and won't pose any threat to our planet.
It will reach its closest approach to the Sun around 30 October 2025 at a distance of 210 million kilometres (130 million miles), putting it just inside the orbit of Mars.
