The Moon's How Old?

Article: http://abcnews.go.com/blogs/technology/2011/08/new-moon-200-million-years-younger-than-thought/

Scientists have long believed that the moon was 4.6 billion years old. However, Lars Borg of the Lawrence Livermore National Lab says that the moon is actually 4.4 billion years old. That makes the moon 200 million years younger than we previously thought it was! Astronauts John Young and Charles Duke of Apollo 16 in April 1972 brought back the oldest piece of moon that we have. Based on the decay of chemical isotopes of the piece of the moon, that oldest piece of moon that scientists believe we have is 4.56 billion years old and two other Apollo samples have been dated at 4.47 billion years. Borg and his colleagues believe this is impossible. Borg feels that either the moon is younger than past studies suggest or everyone's been wrong about how the moon formed. The most common theory about how the moon formed is that the early solar system was so hot, with so many space rocks crashing into each other, that the moon had lots of molten rock which cooled once debris cleared. Other scientists, like Erik Asphaug of the University of California have their doubts about Borg's theory. NASA is staying agnostic on the matter.

This article shows how isotopes are always being used in science. This use of isotopes was to determine how old the piece of moon was. In the article Borg does not dispute the age of the rocks that were tested by isotopes. He uses the age given and his knowledge of the solar system to say that either the moon is younger than we think or that it did not form in the way we believe it did. This article shows how the thoughts and beliefs in science are always changing and how the same method, like dating using isotopes can be used to prove or disprove a belief.