A very small asteroid, circling the Earth while orbiting the sun, has been officially classified as a tiny second moon by NASA.

NASA Tiny Second Moon
Image Credit: NASA/JPL-Caltech

Very small ‘second moon’ states NASA

For almost 100 years, a tiny asteroid has been orbiting the sun on a similar path to Earth. The asteroid, officially known as ‘2016 HO3’ is between 120 and 300 feet in diameter. Due to its small size, it seems to have been happily circling the earth for some time (thought to be about 100 years) without being detected.

It was first identified back in April by the Institute for Astronomy at Hawaii University, on their Pan-STARRS 1 telescope.

“Caught in a little dance”

The asteroid’s orbit has followed a strange back and forth pattern for many decades, getting closer and further away to Earth, but always staying within seemingly fixed parameters.

Paul Chodas, manager of NASA’s Centre for Near-Earth Object (NEO) studies at the Jet Propulsion Laboratory in Pasadena stated, “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.”

This gravitational and celestial arrangement means that it never gets any closer than approximately 38 times the distance of the moon, which results in this mini-moon being “caught in a little dance” with Earth.

Quasi-satellite

The distance is too great for the asteroid to be deemed a true satellite of Earth, but it is the most stable example we have of a near-Earth companion, hence the term ‘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 Chodas.

Companion, but for how long?

It is expected that at some point this ‘second moon’ will leave us at eventually, but it is predicted that it is likely to be around for some time yet. Chodas stated, “this new asteroid is much more locked onto us,” and went on to guess that it would be our companion for “centuries to come.”

For all the doom mongers out there, please note that the scientists involved were quick to point out that our new space friend is no danger to our planet, or our moon.

Other celestial friends

Asteroid 2016 HO3 is not our only companion in space. Along with the moon, which has been around since the earth was formed and unlikely to leave us anytime soon, we have had a number of other asteroids join us on our merry journey.

2003 YN107, was another asteroid that orbited Earth for some time in the early 2000’s but has since left our solar system.

In late 2006, RH120 was spotted by astronomers in Arizona. After initially being dismissed as space debris or the remnants of a previous rocket booster, it was later confirmed as an asteroid circling earth. Perhaps not liking the cut of our jib, it left within a year.

There are two other asteroids, 3743 Cruithne, a three-mile-wide asteroid and 2010 TK7, a Trojan asteroid that also circle the earth as the earth makes its way round the sun.

The European Space Agency has recently discussed far reaching plans to build an outpost between the Earth and the Moon. This would be used to make it far easier to get to and from the moon. Exciting times.