CESKE BUDEJOVICE, Czech, Dec. 17 (Xinhua) -- Czech astronomers from the Klet observatory in the south of the country discovered an unknown asteroid bypassing the Earth at a distance of 600,000 kilometers Friday night, observatory director Jana Ticha said on Sunday.

    Ticha said the asteroid, now designated internationally as 2006XR4, was discovered when it was at its nearest to the Earth.

    The distance is only a little bit larger than the distance between the Earth and the Moon.

    "This is one of the asteroids bypassing us at a very close distance that has been discovered in Europe. A big majority of such discoveries are made by large U.S. observatories," Ticha said.

    The asteroid, moving at a very high speed, belongs to the rare Apollo type whose orbit crosses the orbit of the Earth around the Sun.

    The asteroid measures about 20 meters, and would not bring any damage if it possibly crashed into the Earth as it would probably disintegrate into small fragments on its flight through the atmosphere.

    The monitoring of even such small bodies enhances the knowledge of the structure of a whole population of asteroids, including the calculation of their coming near the Earth and the probability of their crashes into the Earth, Ticha said.