WASHINGTON, June 17 (Xinhua) -- A small asteroid has been found constantly circling the Earth as part of its orbit around the sun, the U.S. National Aeronautics and Space Administration (NASA) announced on Thursday.

NASA scientists said the asteroid, designated as 2016 HO3, has been the Earth's companion for nearly a century, and will probably stay with us for centuries to come.

"Since 2016 HO3 loops around our planet, but never ventures very far away as we both go around the sun, we refer to it as a quasi-satellite of Earth," said Paul Chodas, manager of NASA's Center for Near-Earth Object (NEO) Studies in California.

"Our calculations indicate 2016 HO3 has been a stable quasi-satellite of Earth for almost a century, and it will continue to follow this pattern for centuries to come," Chodas added in a statement posted on the website of the center.

NASA estimated that the asteroid, first spotted on April 27, 2016 by the Pan-STARRS 1 asteroid survey telescope, is between 40 and 100 meters in diameter.

NASA said the asteroid is not going to crashing into us because it never gets closer than 38 times the distance of the Moon. Therefore, it can not be considered as a natural Moon of the Earth because it is so far away from the planet.

The Moon, the only known permanent natural satellite of the Earth, is 384,000 kilometers from the blue planet.

It is not the first time that the Earth has picked up an asteroid companion.

"One other asteroid -- 2003 YN107 -- followed a similar orbital pattern for a while over 10 years ago, but it has since departed our vicinity. This new asteroid is much more locked onto us," Chodas said.