China News Agency, Beijing, January 18 (Reporter Sun Zifa) Li Mingtao, a researcher at the National Space Science Center of the Chinese Academy of Sciences, released an asteroid observation forecast on the 18th, saying that a near-Earth asteroid with a diameter of one kilometer and codenamed 1994 PC1 will be released in Beijing. It flew over the earth at 5:51 a.m. on the 19th, but it would not pose any threat to the earth.

  The flyby is the closest the 1994 PC1 asteroid will come to Earth in the next 100 years, he said.

The closest distance of its flyby is about 1.98 million kilometers from the earth, which is equivalent to about 5 earth-moon distances.

However, this flyby of the asteroid will not pose any threat to Earth.

  In an interview with a reporter from China News Agency, Li Mingtao said that the international permanent number of the near-Earth asteroid 1994 PC1 is 7482. It was discovered by the Siding Spring Observatory in Australia in August 1994. It is estimated to be about 1 km in diameter. Asteroid (S class), its rotation period is about 2.6 hours.

  The asteroid 1994 PC1 is an Apollo-type near-Earth asteroid that takes 572.2 days to orbit the sun once.

The radius of aphelion is 1.793 (au is an astronomical unit, the value is the average distance between the earth and the sun, 1au is about 150 million kilometers), the radius of perihelion is about 0.904au, and the inclination relative to the ecliptic plane is about 33.5 degrees.

Due to its high angle of inclination, the asteroid has a relative speed of 19.56 kilometers per second and more than 70,000 kilometers per hour when it flew over the Earth.

  Li Mingtao pointed out that although this near-Earth asteroid meets the definition of a potentially threatening asteroid, it has no threat to Earth in the next 100 years.

The 1994 PC1 asteroid last approached Earth in 1997, when it was about 9.74 million kilometers away; its next approach will be in 2058, when it will be 22.4 million kilometers away.

Therefore, this flyby will be a good opportunity to conduct fine tracking observations of the 1994 PC1 asteroid. It is believed that global space and astronomical institutions will use the planetary radar system to observe the characteristics of this asteroid.

  He said that when the 1994 PC1 asteroid flew by the earth this time, it will reach a 10.2-magnitude star at its brightest, which is about 50 times dimmer than the faintest star (6th-magnitude star) that the human eye can see. On the full moon, observations may be affected to a certain extent, but for many small and medium-sized optical telescopes, it will be a very good observation opportunity.

  For Chinese regional observers, in the next three days, 19:00 to 23:00 on January 18, Beijing time, 19:00 to 23:00 on January 19, and 19:00 to 22:00 on January 20, astronomical and small Planetary observation enthusiasts can use amateur telescope equipment to carry out 1994 PC1 asteroid observation.