Comet 3I/ATLAS is the interstellar visitor on everyone's lips at the moment, as it continues to make its way through our Solar System on a journey across the Universe.
The vast majority of comets that we know about originated from within our Solar System, and orbit our Sun.
But 3I/ATLAS is different. It originated in deep space and is merely passing through our cosmic neighbourhood.
It was discovered by the Asteroid Terrestrial-impact Last Alert System (ATLAS) on 1 July 2025, and is one of just three such interstellar objects ever seen in our Solar System, the other two being 1I/ʻOumuamua, discovered in 2017, and 2I/Borisov, discovered in 2019.
Very Large Telescope gets a glimpse
Shortly after it was discovered, one of the most powerful ground-based telescopes in the world captured these images showing 3/ATLAS's journey across the sky.
The European Southern Observatory's Very Large Telescope is located in Chile and operates under the dark skies of the Atacama Desert.
These images were captured over the course of about 13 minutes on the night of 3 July 2025, just two days after 3/ATLAS was discovered.
A composite image was produced using multiple frames to show the comet's direction of travel, towards the right of the frame.
And an accompanying video shows 3ATLAS's movement across the sky over the course of 13 minutes.
At the end of the video, the individual frames have been 'stacked' together to provide a hi-res view of the comet.
When these observations were made, this was the deepest and best image of the comet we had.
But we now have images of 3I/ATLAS captured by powerful space observatories like Hubble, Webb and SPHEREx, and the ground-based Gemini North telescope.
These VLT images were captured using the FORS2 instrument, and the data is available in the ESO archive.
What next for 3I/ATLAS?
Interstellar comet 3I/ATLAS is travelling towards the inner Solar System and is will make its closest approach to Earth in late October 2025.
At this point, 3I/ATLAS will be hiding behind the Sun, from our perspective, and will therefore not be visible.
But it will become observable again in December 2025, as it makes its way out of the Solar System and into deep space.
