An asteroid named 7335 (1989 Ja) will "pass by" the earth on May 27, NASA's near earth object Research Center said** It will be the largest and most potentially destructive asteroid close to earth this year.
Researchers estimate that when it is closest to the earth, the distance between it and the earth is 4 million kilometers, which is nearly 10 times the average distance between the earth and the moon. The flight speed is about 21 km / s, which is 20 times faster than high-speed bullets. Before June 23, 2055, this rock will not fly close to the earth again.
Given the large size of the space rock - about 1.8 kilometers in diameter and its close distance from the earth, NASA classified it as a "potential threat", which means that if its orbit changes and hits the earth, it may cause great damage to the earth.
The asteroid is one of more than 29000 near earth objects tracked by NASA every year. According to NASA, near earth objects refer to objects within 48 million kilometers of the earth's orbit. Most of these objects are very small. The "size" of 7335 (1989 Ja) is larger than 99% of the near earth objects tracked by NASA.
In addition, 7335 (1989 Ja) also belongs to "Apollo class" asteroids (asteroids orbiting the sun periodically through the earth's orbit). At present, astronomers know about 15000 such asteroids.
NASA is currently closely monitoring such Neos and recently launched a mission to test whether potentially dangerous asteroids will one day deviate from orbit and collide with the earth. In November 2021, NASA launched a spacecraft called "double asteroid redirection test", which will collide head-on with a 160 meter wide asteroid called dimorphos in the autumn of 2022. It is reported that the collision will not destroy the asteroid, but may slightly change its flight orbit.