The European Space Agency revealed the closest images of comet 3I/ATLAS

Since July, when it was first reported, the interstellar comet 3I/ATLAS It was observed by terrestrial telescopes or close to the orbit of our planet.

However, recently, the European Space Agency (ESAfor its acronym in English) was able to visualize it through a telescope on its spacecraft located in the vicinity of Martewhose lens managed to get close to the object at a distance hitherto not reached.

Meanwhile, the astronomical community is waiting for the approach of the ATLAS to the Tierrato be able to study it in depth.

The unprecedented images of comet 3I/ATLAS published by the European Space Agency

Until September, the determination of the composition, location and trajectory of 3I/ATLAS It depended on ground-based telescopes. However, between October 1 and 7, the probe’s telescope ExoMars Trace Gas Orbiter (TGO), which is located at 400 kilometers from Mars and is controlled by the European Space Agency, He located the object and managed to approach it at an unexpected distance.

The TGO, launched in 2016 to study Mars, had its closest approach to ATLAS on October 3, when it was positioned 29 million kilometers from it.

One of the ESA images that captured comet 3I/ATLAS (white dot). Photo: ESA

So, its Color and Stereo Surface Imaging System (CaSSISfor its acronym in English), a camera what It was actually designed to point towards the surface of the red planet and take high-resolution images, turning its gaze towards the interstellar comet.

Although scientists initially anticipated a modest improvement, the result was an impressive jump in ten times the precisionwith respect to ground-based telescopes.

This reduced uncertainty about the object’s location and helped make the prediction of its trajectory much more accurate.

An ATLAS image taken by a ground-based telescope. Photo: Qicheng Zhang/Lowell Observatory

The orbiter’s camera finally photographed 3I/ATLAS as it moved against a starry background.

Las imagesrevealed by ESA on October 7, show a white point slightly blurry moving down. This point is the center of the comet, comprising its icy-rocky core and its surrounding coma.

Despite the approach, the distance was not enough for CaSSIS to be able to distinguish the nucleus of the comet, but it was able to reveal its coma, that is, the cloud of gas and dust that surrounds it. However, he could not measure the full size of this either, since the brightness of the dust decreases rapidly with distance from the nucleus, meaning that the coma is lost in the noise of the image.

The data obtained by ESA on comet 3I/ATLAS represents the first time that astrometric measurements from a spacecraft orbiting another planet have been officially submitted and accepted by the ESA’s Minor Planet Center. International Astronomical Union, which functions as an information exchange database for observations of asteroids and comets.

Likewise, although ATLAS does not represent any threat, it was a valuable exercise for planetary defense, since the organization demonstrated that it can detect space objects long before they reach Earth and issue, if necessary, warning signals.

Now, after the successful observation with its Mars probe, ESA is following comet 3I/ATLAS with its Jupiter Icy Moon Explorer, another of its spacecraft, and hopes to obtain optimal results in February 2026.

Meanwhile, the agency, as well as the entire astronomical community, awaits the closest passage of the object through our planetwhich will happen in a few weeks, to be able to analyze it in depth.

When will comet 3I/ATLAS approach Earth?

He 3I/ATLAS, First reported on July 1, 2025, it is the third interstellar object known (hence its name «3» «I»), after the discovery of 1I/Oumuamua, in 2017, and 2I/Borisov, in 2019.

However, this comet presents a series of peculiaritiessuch as a very high speed and enormous size, which transform it into a different species from its predecessors. Therefore, the astronomical community is waiting for the day to arrive when it reaches its closest point with respect to the Tierra.

According to what was reported by the NASAthis will happen when placed at a distance estimated to be 1.8 astronomical units (approximately 270 million kilometers) in relation to our planet.

According to the organization, the event will occur in December 2025 and, despite alarming theories, it will not represent a threat to Earth, because the object will pass quite far from it.

A few days ago, the European Space Agency went further and set the exact date on which the comet will reach this point: the next December 19.

Although the phenomenon cannot be seen by the human eye, it will be the period in which specialized teams will be able to observe it clearly. Scientists hope that the approach of the object will allow us to clearly visualize the characteristics that make it different from other comets recorded in the past.