It is known that the third extraterrestrial object has visited the solar system
A mysterious object resembling an asteroid has recently attracted attention from astronomers around the world. The European Space Agency stated on April 2nd that this unknown object might originate from another galaxy, making it the third “interstellar visitor” to have visited the solar system so far.
According to a report by The New York Times on April 2nd, the name of this interstellar object is A11pI3Z, currently located between the asteroid belt and Jupiter, with a distance of several billion kilometers from Earth. Even when it was closest to the Sun in October last year, it was outside the Mars orbit and situated on the opposite side of the Earth from the Sun, so there’s no need for concern about it colliding with Earth.
The night sky captured at dawn on April 23rd in the Miaohe Lake scenic area in Mudanjiang City, Heilongjiang Province (photographed by Xinhua News Agency with photo by Wang Baosheng).
Researchers are currently unable to determine whether this “interstellar visitor” is a rocky asteroid or a comet composed of rocks, ice, and dust. As for its shape and size, they remain unknown.
Hector Trigo Rodriguez, a planetary astronomer at the Spanish research institute under the Space Science Center, mentioned that the trajectory of A11pI3Z is uniquely fast and therefore suggests it may be from another galaxy. Rodriguez estimates its width to be around 40 kilometers. On the other hand, American Harvard University astronomer Avi Loeb speculates it could be about 19 kilometers wide, which would make it quite large for objects traveling between different galaxies.
The first known “interstellar visitor” to the solar system was discovered in October 2017 as a cigar-shaped long object called “Oumuamua,” measuring up to about 400 meters in length. If A11pI3Z is confirmed to be 19 kilometers wide, its mass would be 10 million times that of “Oumuamua.” Initially thought to be an asteroid, the discovery later led researchers to believe it was a comet. The celestial body discovered in 2019, 21/Borisov, is currently the second known “interstellar visitor” to the solar system, analyzed as a comet.