It started out as a small dot moving across a sea of stars in a black and white image, and now has evolved into a large, bright object with a glowing tail, courtesy of some of the best telescopes humanity has ever built.
Comet 3I/ATLAS continues to amaze scientists, astronomers and even mere mortals like.
And unsurprisingly, professional comet-watchers have been utilising our best observing engineering to find out as much as they can, while they can.
That’s because 3I/ATLAS is merely passing through our Solar System, and won’t be around for long.
By late October 2025 it will have disappeared behind the Sun, and will remerge in November 2025.
After that, it will continue its journey through our Solar System, exit it and be gone forever.
Comet 3I/ATLAS is one of only three interstellar visitors ever observed by humanity, so understandably we’re throwing all of our observing prowess at it, while it’s here.
Astronomers have observed the comet with numerous telescope in different wavelengths to learn more about its trajectory and its composition.
It’s a primordial piece of the Galaxy, likely more than seven billion years old. That means it’s probably about twice as old as our Sun.
Here are some of the best images of 3I/ATLAS captured so far.
We begin with the image that started it all. The view of 3I/ATLAS captured by the ATLAS survey telescope in Chile, when it was discovered.
The animation below is made of multiple images of the comet captured by the ATLAS survey, showing its movement across the sky.
Then in July 2025, the Very Large Telescope, based at the European Southern Observatory’s site in the Atacama Desert, Chile, was used to capture the composite below, again showing 3I/ATLAS’s movement across the sky.
And here’s a closeup of 3/ATLAS captured by the Very Large Telescope at the same time.
Later in July 2025, 3I/ATLAS was photographed by the Gemini North Telescope in Hawai‘i.
The telescope’s Multi-Object Spectrograph (GMOS-N) gave astronomers an early view of the comet’s coma, which is the cloud of gas and dust surrounding its nucleus.
These observations helped characterise the chemical composition of 3I/ATLAS early on.
The Gemini North telescope’s Multi-Object Spectrograph also captured this image showing the comet moving across the sky, composed of multiple images taken through red, green and blue filters.
Later in July 2025, the mighty Hubble Space Telescope captured an image of 3I/ATLAS.
Hubble’s observations helped astronomers better estimate the size of the comet’s nucleus, which is made of dust and ice.
The rather unusual image below of 3I/ATLAS as captured using NASA’s SPHEREx (Spectro-Photometer for the History of the Universe, Epoch of Reionization and Ices Explorer) spacecraft, which observed the comet between 7–15 August 2025.
SPHEREx observes in near-infrared, which means it can see elements of objects in space that would be invisible to the human eye.
It was able to analyse light coming from 3I/ATLAS to enable scientists to learn more about the comet’s chemical composition.
SPHEREx detected carbon dioxide gas in its coma and found water ice in the nucleus.
Around the same time that SPHEREx was observing 3I/ATLAS, the James Webb Space Telescope captured these images of the comet.
Like SPHEREx, Webb observes in the infrared, meaning it can see things beyond human vision.
The Webb Telescope found 3I/ATLAS is rich in carbon dioxide and also contains water ice, water vapour, carbon monoxide and carbonyl sulfide.
In late August 2025, the Gemini South Telescope at Cerro Pachón in Chile captured these images of 3I/ATLAS.
Gemini South found that the comet is getting more active and its tail is stretching out longer as it makes its way through our Solar System.
The below image was captured using red, green and blue filters, which explains the colourful streaks in the background.
The telescope was focussed on the comet, tracking its movement across the sky, and so the much more distant, more stationary stars appear as long streaks.
A bit of image processing was carried out on the Gemini South images to ‘freeze’ the background stars and get rid of the streaks, resulting in the final image below.
The Gemini South images captured on 27 August 2025 are the most recent images of 3I/ATLAS so far, but hopefully there will be many more before the year is out.
While the comet is behind the Sun from our perspective, it won’t be possible for our ground-based or even space-based telescopes to catch a glimpse, but there’s already talk of using other missions at Mars and Jupiter to capture images of 3I/ATLAS.
It’s safe to say we’re not done yet, and that there are hopefully many more images – and discoveries – to come.