Small asteroid is Earth’s companion
There is a newly discovered asteroid called 2016 HO3 that because of it’s orbit, never strays too far from Earth. Scientists are calling it a “quasi-satellite” of our planet.
“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 from NASA’s Center for Near-Earth Object (NEO) Studies at the Jet Propulsion Laboratory in Pasadena, California.
“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. 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 as Earth’s companion for centuries to come.”
As 2016 HO3 circles the sun, it loops around Earth as well. 2016 HO3’s orbit is tilted slightly relative to that of Earth, so the asteroid also bobs up and down through our planet’s orbital plane.
“The asteroid’s loops around Earth drift a little ahead or behind from year to year, but when they drift too far forward or backward, Earth’s gravity is just strong enough to reverse the drift and hold onto the asteroid so that it never wanders farther away than about 100 times the distance of the Moon,” said Chodas.
“The same effect also prevents the asteroid from approaching much closer than about 38 times the distance of the Moon. In effect, this small asteroid is caught in a little dance with Earth.”
Scientists discovered the asteroid on April 27 by using the Pan-STARRS 1 survey telescope in Hawaii. Researchers believe the asteroid is between 130 feet and 330 feet wide (40 to 100 meters).