In recent days, the international astronomical community has focused its attention on a rare phenomenon.: the arrival of comet 3I/ATLAS, also provisionally known as A11pl3Z. This object, detected on July 1 by the ATLAS system — a NASA-funded network of telescopes — is the third interstellar visitor officially recognized as crossing our solar system, after the striking 'Oumuamua in 2017 and Comet Borisov in 2019.
The uniqueness of 3I/ATLAS lies not only in its origin, but also in its size and speed.Calculations made to date indicate that its diameter is between 20 and 40 kilometers, making it the largest interstellar object observed so far. Its displacement is about 68 kilometers per second. (more than 240.000 km/h), confirms its foreign nature, since it far exceeds the speed that would allow any body to remain trapped by the Sun.
An origin beyond the solar system
One of the aspects that most intrigues scientists is the origin of 3I/ATLAS. Everything points to it coming from the galactic disk, a star-dense region within the Milky Way. According to experts, these objects can be ejected from their star systems by gravitational interactions, wandering through interstellar space for millions of years until, by pure chance, they pass through planetary systems like ours. To better understand the formation of objects like this, we recommend reading our article on new advances in the exploration of the solar system.
Astronomers from institutions such as the Instituto de Astrofísica de Canarias and the Rubin Observatory in Chile are taking advantage of the opportunity to track its trajectory and study its composition and properties in depth. Early analysis suggests the presence of a coma (fuzzy envelope) and a small tail, signs of cometary activity that allow us to deduce the sublimation of primordial ice trapped since its formation. For a deeper understanding of the composition of similar objects, see Unraveling the mysteries of exocomets.
No danger to the Earth
Despite the spectacular nature of the discovery, there is no cause for alarm. According to the trajectory calculated by experts from NASA, ESA and the Minor Planet Center, 3I/ATLAS's closest point to our planet will occur at the end of October, when it will travel along about 1,35 astronomical units from Earth (approximately 202 million kilometers, beyond the orbit of Mars). The object will continue its journey through the inner solar system, approaching the Sun on a perfectly calculated trajectory that keeps it away from any risk of direct impact. To better understand how risks related to near-Earth objects are assessed, see frozen water in the universe.
During his journey, will be out of the danger zone for our planet and, in fact, the scientific community has already made it clear that the probability of collision is zeroIts path is monitored daily using the most advanced minor body tracking systems, involving both professional observatories and amateur astronomers from around the world.
A cosmic laboratory for science
Beyond the celestial spectacle, the true importance of 3I/ATLAS lies in the unique scientific opportunity that your passage represents. These objects, coming from environments outside the solar system, They store unaltered information about the chemistry and structure of other galactic regionsAnalyzing their composition, the reflection of the light they emit, or their cometary activity will allow researchers to reveal details about the formation of star systems and the materials present in the early universe. To better understand the processes of planetary formation, see how planets are formed.
At this time, more than twenty observatories spread across the globe are involved in tracking the comet. Teams such as the IAC, with its telescopes on Teide and La Palma, have recorded images that show the beginning of cometary activity and contribute to accurately defining both its orbit and its physical nature. The use of large ground-based and space-based telescopes, such as the Webb, will also allow determining parameters such as albedo (reflectivity), surface temperature and rotational dynamics, key data to know the real size and shape of the object.
A phenomenon for history
The discovery of 3I/ATLAS has meant a authentic international mobilizationSince the object's inclusion on the IAU and NASA/JPL confirmation list, coordination between agencies, universities, and observatories has allowed for the collection of high-quality data in record time. This comet's activity is expected to intensify as it approaches the Sun, making observations especially relevant starting in September, although it will be invisible from Earth for a few weeks due to its proximity to the Sun. Later, when it reappears in the night sky, researchers will have a second opportunity to examine it in detail before it continues its journey into deep space.
The phenomenon is not only fascinating for science, but also contributes to improving the international observation protocols and opens the door to new discoveries, especially with the entry into operation of state-of-the-art telescopes such as the Vera Rubin Observatory, which could allow the detection of dozens of interstellar objects in the near future. To understand how interstellar objects can be detected and studied in the future, check out our article on other interstellar objects in the universe.
The appearance of 3I/ATLAS, a body that has traveled for millions of years through the confines of the galaxy before crossing our path, represents a double milestone: on the one hand, a unique opportunity to analyze matter from other solar systems and, on the other hand, the realization that our cosmic environment is dynamic and mutable. Thus, science takes advantage of these fleeting visits to better understand the origin of the planets, the chemistry of the universe, and the evolution of the Milky Way itself. The expectation generated is great, but the rigor and collaboration They will be the ones who extract the maximum knowledge from this unparalleled interstellar comet.