You may have heard of the hype about Pluto becoming a "pluton" together with its moon. Then there's the proposed 12-planet set-up for our solar system. Now, some astronomers are considering the moon a planet, along with 53 other planet candidates.

According to the new definition of planet proposed by the International Astronomical Union, any round object orbiting the sun is a planet, unless it already has a planet of its own to orbit around. However, there's this thing called the barycenter, which is the center of all gravity. If the barycenter is "outside the larger object, then the smaller object is a planet." That's the reason why Pluto's moon Charon is being considered a planet by some astronomers.

But back to the barycenter. At the moment, the system's barycenter is the earth. But in a couple of a few billion years, the barycenter will "move outside the Earth as the Moon recedes." That this, if the Earth or Moon still exists.

Whether our moon, Pluto, or various asteroids will be considered as planets will be discussed soon as authorities will vote on the new definition of planet on the 24th at the IAU meeting in Prague.