Somewhere between 120 ft (40 m) and 300 ft (100 m) in size, our little traveling companion is estimated to have been in step with our orbit for about 100 years now, and will keep us company for many hundreds more. Too far away to be identified as a satellite to our planet, it is stable enough at the moment to be seen as a near-Earth companion body, or "quasi-satellite."

"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 NEO Studies at NASA's Jet Propulsion Laboratory (JPL). "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."