Research findings show that a second temporary moon is the norm in our planet, noting that what looked like a spent rocket stage which was seen orbiting the Earth in 2006 was in fact asteroid 2006 RH120, a natural satellite like the moon.

According to a team of astrophysicists from Cornell, the 2006 RH120, which measured just a few meters in diameter could be a second temporary moon. By 2007, it left the Earth's orbit in search of a new cosmic companion.

The team from Cornell, astrophysicists Mikael Granvik, Jeremie Vaubaillon, Robert Jedicke, said temporary satellites are a result of the gravitational pull of Earth and the Moon which pull on one another and also pull on anything else in nearby space.

According to reasearchers, among the most common objects that are pulled in by the Earth-Moon system's gravity are near Earth objects (NEOs) which are comets and asteroids that end up in orbit and eventually brought near Earth.

The scientists modeled the way our Earth-Moon system captures these NEOs to understand how often additional moons come and how long stay. Their findings show that the Earth-Moon system captures NEOs quite frequently.

"At any given time, there should be at least one natural Earth satellite of 1-meter diameter orbiting the Earth," the team said. These NEOs orbit the Earth for about ten months, enough time to make about three orbits, before leaving.

If the findings of the study are correct, then chances for a manned mission to an asteroid increase. Now astronauts won't have to go all the way out to an asteroid to learn about the Solar System's early history but they can wait for an asteroid to come near the Earth, researchers said.