3I ATLAS interstellar comet tail mystery has become a major focus of current space research. Scientists are closely observing comet 3I/ATLAS, an interstellar object passing through the Solar System. The Hera spacecraft and Europa Clipper mission will soon fly through the interstellar comet tail, offering a rare opportunity to study its composition, mass loss, and interaction with the solar wind. These observations may reveal key insights into the 3I ATLAS comet’s structure, magnetic field influence, and the possible differences between natural and interstellar bodies.

3I ATLAS interstellar comet tail mystery

3I ATLAS interstellar comet tail mystery has become an important topic in space research. Scientists are studying the comet 3I/ATLAS as it moves through the inner Solar System. It is only the third known interstellar object, after ‘Oumuamua and Borisov.

As it approaches perihelion, the closest point to the Sun, the comet has developed a long and expanding tail. Scientists have detected significant emissions of water and hydroxyl ions. These ions, produced by the breakdown of water molecules, can influence the magnetic field within the Solar System.

Hera and Europa Clipper Spacecraft to pass through 3I ATLAS interstellar comet tail

A rare opportunity has emerged for the Hera and Europa Clipper spacecraft to pass through the tail of comet 3I/ATLAS. Both spacecraft are heading toward their primary missions but will cross the comet’s tail during their journey. Hera will pass between October 25 and November 1, and Europa Clipper between October 30 and November 6, 2025. Hera will pass at a distance of 8 million kilometers from the comet’s nucleus, and Europa Clipper at 8.2 million kilometers.

How comet tails behave?

The comet’s movement away from the Sun does not mean its tail trails behind it. The tail consists of particles pushed away from the comet’s surface by the solar wind, always pointing opposite the Sun. Therefore, comets can sometimes appear to move tail-first.

To estimate the tail’s direction, astronomers used a model called “Tailcatcher,” which calculates the comet’s tail path based on solar wind speeds. However, its accuracy depends on available solar wind data, which is often delayed. This limitation makes it difficult to predict the spacecrafts’ exact interaction with the comet’s tail.

Hera and Europa Clipper Spacecraft scientific instruments and observations

Hera lacks instruments to detect ions or magnetic structures in the 3I ATLAS interstellar comet’s tail. However, Europa Clipper carries plasma and magnetometer instruments capable of measuring these phenomena. These could detect changes in the magnetic field caused by the comet’s charged particles.
Whether mission controllers will act in time is uncertain, as there is little time to adjust spacecraft operations. If they succeed, this will be the first time humans directly sample an interstellar comet tail.

3I ATLAS Interstellar Comet transition from anti-tail to tail

Images from the Nordic Optical Telescope in Spain showed that the anti-tail of 3I/ATLAS, which pointed toward the Sun earlier in 2025, turned into a regular tail in September 2025. No Earth-based observations are possible in October, as the comet is currently near the Sun in the sky.

Scientists David Jewitt and Jane Luu estimated the comet’s mass loss rate and concluded that carbon dioxide is the main driver of its activity. The Webb telescope data confirmed that about 87% of emissions are CO₂, 9% CO, and 4% water vapor.

3I ATLAS Interstellar Comet Hubble and other telescope findings

The Hubble Space Telescope captured detailed images of 3I/ATLAS on July 21, 2025, showing a jet-like anti-tail structure. This feature was explained as sunlight scattering from ice fragments released by sublimating carbon dioxide.

Further studies by Eric Keto and Avi Loeb proposed a model showing how the anti-tail transformed into a regular tail as the comet approached the Sun. The increase in temperature caused more ice fragments to form, creating a brighter scattering effect that later shifted to dust-driven emission as the comet moved closer to the Sun.

3I ATLAS Interstellar Comet mass and surface loss

From July to October 2025, the comet lost around 2 million tons of material—just a tiny fraction of its estimated 33 billion-ton total mass. The data suggest that only a thin surface layer, about 4 centimeters thick, has evaporated.

3I ATLAS Interstellar Comet speculative theories and next steps

Some researchers, like Adam Hibberd, suggested that if the comet were an artificial object, the anti-tail transition could indicate a controlled maneuver. However, this remains speculation. Upcoming observations in December 2025, when 3I/ATLAS will be closest to Earth, are expected to provide clearer answers.

The object will receive intense solar radiation during perihelion. Scientists hope that further data from Hera, Europa Clipper, and ground-based telescopes will determine whether 3I/ATLAS behaves like a natural comet or reveals unusual features.

FAQs

Q1: What is the 3I ATLAS interstellar comet tail mystery?
It refers to the scientific study of comet 3I/ATLAS, an interstellar object with a changing tail structure and unique composition, being analyzed by the Hera and Europa Clipper missions.

Q2: When will Hera and Europa Clipper cross the 3I ATLAS comet tail?
Hera will pass between October 25 and November 1, 2025, while Europa Clipper will cross between October 30 and November 6, 2025, during their respective missions.