Earth’s gravitational pull has likely drawn in three different moons, according to a University of Melbourne astronomer.
Dr. Tanya Hill found Earth may have two mini-moons in addition to the moon people see in the night sky. A large asteroid discovered in June is likely in orbit around Earth, and Hill found Earth almost always has another mini-moon in orbit.
Such a mini-moon would be small, less than 30 feet in diameter, and continually caught in a tug of war between the gravity of the Earth, the moon and the sun. Hill’s findings build on recent research on mini-moons.
“Minimoons are scientifically extremely interesting,” Dr. Robert Jedicke, an astronomer at the University of Hawaii who has published research on mini-moons, wrote in a press statement for a separate study published in July.
“A minimoon could someday be brought back to Earth, giving us a low-cost way to examine a sample of material that has not changed much since the beginning of our solar system over 4.6 billion years ago,” he said.
Both Hill and Jedick used computer simulations to determine that mini-moons must exist, but to date, only one mini-moon has ever been directly observed. The object was a small asteroid, about 10 feet in diameter, and orbited the Earth from April, 2006, to September, 2007. NASA funded both those studies.
Earth’s largest mini-moon, asteroid 2016 HO3, orbits the sun in such a way that it never strays too far from Earth, making it a “quasi-satellite” of our planet. The asteroid’s exact size is unknown, but researchers believe that it is between 130 feet and 330 feet wide.
Neither mini-moon poses a threat to Earth, and never gets closer than 9 million miles from our planet. In comparison, Earth’s larger moon is an average distance of a quarter-of-a-million miles away.
Asteroid detection programs have found more than 13,500 near-Earth objects of all sizes. Roughly 1,500 new near-Earth objects are found every year. Approximately 953 near-Earth objects have already been found this year, according to the Minor Planets Center.
NASA estimates more than 90 percent of “world-killer” asteroids with a diameter of more than 3,000 feet have already been discovered. The agency is focused on finding objects that are 450 feet in diameter or larger, which could devastate a city or country if they struck Earth.
Send tips to andrew@
All content created by the Daily Caller News Foundation, an independent and nonpartisan newswire service, is available without charge to any legitimate news publisher that can provide a large audience. All republished articles must include our logo, our reporter’s byline and their DCNF affiliation. For any questions about our guidelines or partnering with us, please contact licensing@dailycallernewsfoundation.org.