Humanity knows only about 40 percent of large and crossing the Earth's orbit asteroids and comets, while more than 25 thousand of such objects are known today, according to a report published on the website of the Scientific and Technical Subcommittee of the UN Committee on the Peaceful Uses of Outer Space …
"It is estimated that only about 40 percent of the significant near-Earth objects have been identified," the report says.
The document notes that in 2020, the worldwide network of astronomical observatories, located in more than 40 countries, has collected almost 39.5 million records of observations of asteroids and comets. As of April 17, 2021, scientists were aware of 25,647 near-Earth objects. Moreover, in 2020, 2959 such objects were found - a record number.
Earlier, the scientific director of the Institute of Astronomy of the Russian Academy of Sciences Boris Shustov told RIA Novosti that experts know only about every tenth cosmic body more than 100 meters in size, and only one percent of bodies of about 50 meters, such as the Tunguska meteorite, are known. At the same time, such small bodies as the one that fell in Chelyabinsk do not at all lend themselves to preliminary detection at a long distance.
Also, according to Shustov, Russia is opening an insufficient number of dangerous space objects in comparison with other countries. So, as of January 2019, the Russian contribution to the detection of dangerous asteroids and comets was 0.1 percent, and the United States made the main contribution. At the beginning of 2019, experts knew about 18 thousand dangerous objects, of which 99 percent are asteroids.
In connection with the urgency of such a threat, the earlier head scientific institute of Roscosmos, TsNIIMash, announced that it intends to create a national center for tracking and tracking dangerous asteroids and comets.