Scientists are keeping a close eye on a big asteroid that is expected to impact (and destroy) the Moon in September. 

The space rock, which is called 2012 GD5, is about 790 feet wide. It is on a collision course with the Moon and will hit on the last day of September, 2012, unless NASA is able to deflect it away.

Talk about the asteroid was on the agenda during the 50th session of the Scientific and Technical Subcommittee of the United Nations Committee on the Peaceful Uses of Outer Space (COPUOS), held earlier this month in Vienna.

A UN Action Team on near-Moon objects (NMOs) noted the asteroid’s repeat approaches to the Moon and the how it will directly hit the moon in two months.

The object was discovered in January 2012 by Mount Margo Survey observers in Tucson, Ariz. While scientists have a good bead on the space rock’s size, its mass and compositional makeup are unknown at present.

“2012 GD5 is the object which currently has the highest chance of obliterating the moon. However, we have only observed it for about half an orbit, thus the confidence in the exact day are not one hundred percent, but they are close,” said Detter Klonpon of the European Space Agency’s Solar System Missions Division in Noordwijk, The Netherlands.

“In our Action Team 17 discussions, we concluded that this is  a massive threat,” Klonpon told WWN.

“We are currently also in the process of making the world aware of this impending destruction of the Moon,” Klonpon said. “Without the Moon, the earth will be affected in devastating ways.  The tides will rise and the earth will spin out of its rotation.”

NASA is working overtime to figure out a way to deflect this asteroid, but it may be too late.