Earth has two moons, groups of scientists across the world have always argued. One is the waning nightlight we all love, while the other is a tiny asteroid, no bigger than a car. News and studies about this scenario was posited by the scientists in a paper published on 20th December 2011 in the planetary science journal ICARUS. The researchers say there is a space rock at, one meter or 3.3 feet wide orbiting Earth at any given time. They're not always the same rock, but rather an ever-changing cast of ‘temporary moons’.
Our planet's gravity captures the asteroids as they pass the planet on their way around the sun. When one asteroid is drawn in, it typically makes three irregularly shaped swings around Earth and sticks around for about nine months before hurtling away.
According to the researchers, very little attention has been paid to Earth's natural satellites other than the moon, despite the fact that they're sure to exist. "There are lots of asteroids in the solar system, so Earth’s chances to capture an asteroid at any time, is not surprising," explains, co-author Jeremie Vauballion, an astronomer at the Paris Observatory in France.
The researcher’s results are consistent with observations of one such "temporarily-captured asteroid" that is believed to have orbited Earth for about a year starting in June 2006. The object, labeled 2006 RH120, was discovered by the Catalina Sky Survey in Arizona and was estimated to be between 3 to 6 meters wide. "Objects of this size are too faint to be detected when being at a distance of, say, a few lunar distances from the Earth," Gravnik told Life's Little Mysteries. "When coming closer during their orbit, they are moving too fast to be detected, because the limited amount of photons is spread over too many pixels." NASA's Spaceguard Survey tracks the paths of all Near-Earth-Objects (NEOs) in Earth's neighborhood that are larger than 0.6 miles (1 kilometer) in diameter, but the scientists are less concerned with bodies that are too small to pose a threat to Earth.
There are no doubts about the fact that there are limitations in finding our second moons, but an observatory called the Large Synoptic Survey Telescope (LSST), planned to open in Chile in 2015, could change that. Statistic study is also needed to see where and how to look for these extra ’moons’ or asteroids. Some asteroid impact hazard experts believe that temporarily captured NEOs would be comparatively easy to get to, and getting back from it wouldn't take an especially powerful rocket, plus the round-trip time would be short. This could therefore help in studying more about our satellite, the moon, that has long been a symbol of mystery and intrigue for scientists across the globe.
Photo by International Business Times.
