Ananova:

British and German scientists say they have measured the exact age of the moon for the first time.

Researchers from Oxford University and the Universities of Cologne and Muenster have determined the moon is 4.527 billion years old.

The estimate, made using the latest technology, is now considered to be the most accurate estimate in human history.

The research team, consisting of both German and British metallurgists, calculated the moon's likely birth date by examining moon rocks brought back by Apollo astronauts.

They measured the rate of decay of a certain isotope of the mineral Tungsten (Tungsten 182), common in moon rocks, to calculate how old they were.

According to the team all radioactive isotopes decay, changing to different nuclear products over time.

The researchers looked at the ratio of the amount of the parent radioactive isotope to the amount of the daughter nuclear product, and knowing the rate of decay of the parent isotope, they could calculate how long the moon rock had existed.

They admit that researchers in the future may come up with an even better guess, but say the current estimate, the best ever, is accurate "to a few tens of millions of years".