People usually think that the moon is the only satellite our planet has. However, in a new study, scientists suggest that Earth has other "mini-moons."

According to the researchers, the other moons are small asteroids that were captured in the planet's orbit. Due to its 1- to 2-meter size, it moves out of Earth's orbit quickly which has made it quite hard to detect. Up to this day, only a single mini-moon has been discovered. The rocks slingshot themselves back into space after appearing in the sky.

Findings Of The Study

"These asteroids are delivered towards Earth from the main asteroid belt between Mars and Jupiter via gravitational interactions with the Sun and planets in our solar system," stated Dr. Robert Jedicke, lead author, based at the Institute of Astronomy at the University of Hawaii. 

"The challenge lies in finding these small objects, despite their close proximity," he added.

The study was done by an international team of astronomers and was published in Frontiers in Astronomy and Space Sciences. According to them, this could give scientists a chance to explore the life cycle of asteroids.

The study stated and the first mini-moon was seen 12 years ago. This was the first time scientists have detected any natural object that orbited the Earth except for the Moon. The rogue asteroid which was captured by the planet's gravity proved to be a great finding.

Now, scientists say that new telescope technology called the Large Synoptic Survey Telescope, or LSST, could significantly help them spot more similar objects on a regular basis. If this would happen, researchers can study the mini-moons and use their discoveries as a basis for the movements of asteroids in the solar system.

About The Mini Moons

"Mini-moons that spend significant time in orbit around Earth allow us to study the density of these bodies and the forces that act within them, and therefore solve this mystery," said Dr. Mikael Granvik, planetary scientist for the Luleå University of Technology in Sweden and the University of Helsinki in Finland, who also authored the study.

He added that they still do not know whether the asteroids are fragile sand piles, monolithic rock blocks, or a mix of both.

The rocks are called Temporarily-Captured Orbiters or TCOs, and Temporarily-Captured Flybys or TCFs by researchers. The former completes a revolution around Earth. On the other hand, the latter just stay at the planet for a short time before it flies away.