Experts at the Purple Mountain Observatory respond to "4.29 asteroid hit the earth": alarmist
China News Service, Nanjing, April 15 (Yang Yanci) responded to a number of media reports recently on "NASA Warning: Asteroids arrived on Earth on April 29! At a speed of 9 kilometers per second, they may hit the earth." This statement, Chinese Academy of Sciences Zhao Haibin, chief scientist of the Near-Earth Astronomical Telescope Group at the Purple Mountain Observatory, responded on the 15th that this statement is alarmist and has zero chance of hitting the earth.
It is reported that this rumor refers to a potentially threatening asteroid officially numbered 52768, which was discovered by the NEAT project in the NASA "Space Guardian" program in 1998, also known as 1998OR2. This asteroid has a diameter of about 2.5 kilometers. Once it hits the earth, it will cause global catastrophe, so it has attracted much attention.
Zhao Haibin said that humans discovered the asteroid very early and began to monitor it. After more than 20 years of extensive tracking observations by multiple monitoring equipment around the world and constantly updating its orbital parameters, the orbit of the 52768 asteroid has been set quite accurately. It is estimated that it will fly over 6.28 million kilometers away from the earth at 17:56 pm on April 29, 2020, Beijing time at a speed of 8.69 kilometers / second. It has zero chance of hitting the earth during this flyby.
The Purple Earth Mountain Observatory's Near-Earth Object Telescope has also been monitoring the asteroid 52768, and reported monitoring data to the International Asteroid Center (MPC): As early as September 1, 2013, the Near-Earth Object Telescope had carried out on the asteroid 52768. Monitoring; on April 4, 2020, as the asteroid gradually approached the Earth, the Near-Earth Astronomical Telescope tracked it again.
In fact, the potential threat of an asteroid flying across the earth is not a small probability event. The two newly threatened asteroids 2020DM4 and 2020FO5 newly discovered by the Near-Earth Astronomical Telescope at the Purple Mountain Observatory both flew the earth recently.
Among them, the 2020DM4 (approximately 160 meters in diameter) discovered on February 26 will fly over the earth at 18:05 on May 1, Beijing time, and it is 7.05 million kilometers away from the earth at a speed of 6.39 km / s; March 23 The discovered 2020FO5 (about 280 meters in diameter) flew across the earth at 5: 2 am on April 12, Beijing time, with a distance of 21 million kilometers and a speed of 27.5 kilometers / second. Since these two asteroids are newly discovered targets, the monitoring time is relatively short, and the orbital uncertainty is large, so it is necessary to strengthen monitoring and early warning.
"The risk of an asteroid hitting the earth is tangible and cannot be stolen, but there is no need to over-interpret it." Zhao Haibin believes that hitting the earth by near-Earth objects is one of the major crises facing the earth and human living environment, and it is also a scientific issue that scientists focus on . With the increasing number of discoveries of near-Earth objects, humans have existed in danger from ignorance, and can now carry out a certain degree of monitoring and early warning, and carry out layout and preparations for impact defense.
Zhao Haibin believes that due to the complex dynamic environment suffered by near-Earth objects, orbital drift caused by gravitational effects from massive objects and their own characteristics will cause orbit changes, which may lead to future collisions with the Earth and near-Earth objects. The monitoring and early warning of celestial bodies is a normalized work that needs long-term and continuous development. (Finish)