3I/ATLAS keeps astronomers and fans of the universe in suspense who have followed its trajectory since it entered the solar system and crossed perihelion on October 29. The truth is that this is not the first time that an interstellar comet has come so close, since in 2017 and 2019 two extrasolar celestial bodies did it too: 1I/Oumuamua y 2I/Borisov.
As these are two interstellar visitors never seen before, space agencies such as the NASA and the European Space Agency (ESA) made all their technology available with the purpose of collecting as much data as possible, since their structures could differ from the comets that lie in our planetary system.
Oumuamua It was the first object from another distant star to grace our system. It was discovered in October 2017 by the Robert Weryk telescope used by Pan-STARRS in Hawaii.
Its shape was like a cylinder, elongated, similar to a cigarette, of a reddish tone. Those who located him that time baptized him with that name, which in Hawaiian means “Messenger from distant lands who arrives first”according to the scientific article that NASA published on its website.
The experts deciphered that 1I/Oumuamua It was up to 400 meters longperhaps up to ten times as long as it is wide. According to subsequent research, that proportion was the largest recorded of any asteroid or comet observed to date. That detail became a hint at how solar systems could be created in other regions of the universethey proposed.
When the comet passed through our planetary system it was an encouraging surprise, since it was bet that wandered through the Milky Way for more than 100 million years until it reached our star system. “Oumuamua varies by a factor of 10 as it rotates on its axis every 7.3 hours. No known asteroid or comet in our solar system exhibits such a wide variation in brightness, with such a large length-to-width ratio. The most elongated objects we have observed to date They do not exceed three times the length and width”, noted at that time the astronomers of the ESO Very Large telescope, which is located in Chile.
Furthermore, it was known that its structure was dense, composed of rock and possibly metals, it had no water or iceand that its surface turned red due to the effects of cosmic ray irradiation for hundreds of millions of years. The celestial body passed just 3,862,416 million kilometers from the Sun.
2I/Borisnov It was discovered by the Crimean amateur astronomer Gennady Borisov on August 30, 2019 and after the commotion that Oumuamua caused, this one too became a global phenomenon for coming from outside our planetary system.
When knowledge of the comet became known, NASA’s Hubble Space Telescope immediately captured some images in October and December of that same year, as it crossed our solar system. at a speed of approximately 177,000 kilometers per hour. “The images showed a large amount of dust around a bright nucleus, although this was too small to be observed by Hubble,” the US space agency described in one of its articles published in 2020.
NASA studies revealed that the comet’s nucleus was made up of a dispersed agglomeration of ice and dust particles. Although the age could not be detailed, It was speculated that it was older than our solar system.
As for 3I/ATLAS, although it is currently behind the face of the Sun with respect to the Earth, it was learned that It was created more than 7 billion years ago. In addition, the Hubble Space Telescope allowed astronomers to learn about the size of the frozen core, 300 meters and 5.6 kilometers in diameter.
Like 2I/Borisov, ATLAS has a structure of rocks and ice. As it approached the star, it began to release gases and dust that ESA probes detected at a great distance.
At the beginning of December it will be visible again in space and there it will head towards our planet, although it does not represent a danger to human life. will approach 270 million kilometers of the Earth. Experts pointed out that it will not be visible from here and only orbital telescopes will have the capacity to take photos of it.
