The world of space research is revolutionized by the discovery of comet 3l/ATLASwhich is located in the orbit of the planetary system.
Discovered by an organism of the NASAthis object presents particularities very different from those of other known phenomena.
The details of its composition, its route and when it will pass through the vicinity of the planet in which we live. Does it represent a danger to humanity?
The comet 3I/ATLAS It was first reported on July 1, 2025, after being detected by the ATLAS study telescope, funded by the NASAlocated in Río Hurtado, Chile.
This is 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 peculiarities that transform it into a unique species never seen before.
The image of the interstellar comet 3I/ATLAS captured by the Hubble Space Telescope. Photo: Archive
External origin and hyperbolic trajectory
Orbital calculations show that comet 3I It was not formed in our solar system. This is based on the fact that it has a hyperbolic trajectorythat is, it will pass close to the Sun only once and then leave the system forever.
Instead of orbiting the Sun like traditional comets, it will circle around the Sun at high speed and continue its route into deep space. This way of moving can only be explained if it comes from another star system, possibly expelled by the gravity of a giant planet or by a collision at its place of origin.
Unprecedented speed
The ATLAS travels at a speed greater than 220,000 kilometers per hourestablishing it as the fastest interstellar comet ever recorded.
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What is happening with the 3I/ATLAS? NASA activated its planetary defense protocol against the comet
This not only makes it a difficult object to study, but also makes it exceptional. It is expected that, as it approaches the Sun, its acceleration will increase, making its passage through the interior of the planetary system even shorter.
Anomalous composition
Although the 3I is a active comet —that is, it has an icy core that releases gas and dust when heated—its composition does not completely match that of known comets.
Studies indicate that It has less water than expected. In addition, its dust has been determined to be similar to that of certain carbon-rich meteorites, suggesting that it formed in an environment very different from that of our solar system.
Particular nickel alloy
The comet contains a nickel alloy never before observed in nature. Scientists detected that it is emitting a feather which contains about four grams of nickel per second and, surprisingly, shows no traces of iron.
This combination generates a compound known as nickel tetracarbonylwhich until now had only been produced through human-generated industrial processes.
A strange and moving tail
The first images recorded by 3I/ATLAS showed a jet of about 6,000 kilometers directed towards the Sun, instead of away from it.
Under typical conditions, according to Live Sciencethe tail of a comet is formed when it is heated by the Sun, so gases and dusts are released from its surface and are pushed by the solar wind in the opposite direction to the star.
This phenomenon, called «anti-cola«, contradicts the typical behavior of comets. Typically, as we said, the solar wind pushes dust and gas in the opposite direction to the solar star.
The physical reasons for this have to do with the fact that the largest fragments ejected from the nucleus do not immediately respond to the solar wind, but rather spread throughout the comet’s orbit, both in front of and behind it.
The 3I and its trajectory. Photo: Gemini Observatory/NOIRLab/ NSF/AURA /K. Meech (IfA/U. Hawaii).However, a preliminary study by astronomers David Jewitt y Jane Luudated in August, provided new images, which show that the comet underwent a notable transformation: it went from exhibiting a tail facing the Sun to develop a more conventional tail, projecting in the opposite direction.
A greater mass than expected
Estimates suggest that comet 3I could be up to a thousand times more massive than 2I/Borisov and a million times more than 1I/Oumuamua. Still, it moves faster than both, making it a unique object in both size and kinetic energy.
Although its exact dimension is not yet known, observations estimate that it could be up to 11 kilometers.
Possible origin in the oldest regions of the galaxy
Some studies suggest that the comet could come from the thick disk of the Milky Way, a region made up of extremely old stars.
If this theory is confirmed, there is the possibility that 3I/ATLAS contains formed material even before the birth of the Sun.
A mystery that will continue its journey
After reaching perihelion (the closest point to the Sun), the comet will temporarily disappear behind the glow of the solar star and will continue its journey back towards interstellar space.
The question then is when it will pass close to Earth and if it will be visible to human eyes.
Is 3I/ATLAS dangerous for planet Earth?
The US National Aeronautics and Space Administration, better known as NASA activated its planetary defense protocol against 3I/ATLAS, in response to the “inexplicable” behavior of this comet.
Comet 3I/ATLAS does not represent a danger to Earth. Photo: Wikipedia (CC BY-SA 4.0)The protocol was made official through the MPEC bulletin (Minor Planet Electronic Circulars), published by Minor Planet Center from Harvard, an organization that operates under the authority of the International Astronomical Union (IAU) and is funded by NASA.
Despite the activation of this defense mechanism, 3I does not represent a danger to the Earth. The US agency confirmed that it will not approach our planet less than 1.8 astronomical units (approximately 270 million kilometers).
Although the comet will not be visible to human eyes, it is estimated that specialized teams They will be able to see it more clearly in December 2025when it is the moment that is closest to our planet.
Currently, 3I/ATLAS is being approaching perihelionand is estimated to reach this point around October 30, 2025.
