How Old is Moon?
The Age of the Moon predicted to ~ 4.36 Billion Years
Scientists claimed that the Age of the moon: ~ 4.36 billion years, i.e. nearly 200 million years less than what earlier predicted. Thus, the moon could be younger than earlier thought, as per the Scientists.
Existing Theory: The existing theory of the moon's origin is that it was formed by a massive impact b/w a big planet-like object and Earth. The energy of the impact was satisfactorily high that the moon formed from melted material that was expelled into space. As the moon cooled, this magma solidified into different mineral components.
- New Theory: Now detailed analysis of lunar rock samples thought to have been derived from the original magma has given scientists a new estimate of the moon's age at ~4.36billion years.
As per this theory for lunar formation, a rock type called "ferroan anorthosite" or FAN - is the oldest of the moon's crustal rocks, but scientists have had difficulty dating FAN samples.
- The Research team analyzed the isotopes of the elements lead and neodymium to place the FAN sample's age at 4.36 billion years. This figure is significantly younger than earlier estimates of the Moon's age that range as old as the age of the solar system at 4.568billion years.
- The new, younger age obtained for the oldest lunar crust is similar to ages obtained for the oldest terrestrial minerals - zircons from Western Australia - suggesting that the oldest crusts on both Earth and moon formed at about the same time, and that this time dates from shortly after the giant impact.
- The study is the first in which a single sample of FAN yielded consistent ages from multiple isotope dating techniques.
- The result strongly suggests that these ages pinpoint the time at which the sample crystallized.
- The extraordinarily young age of this lunar sample either means that the moon solidified significantly later than previous estimates, or that we need to change our entire understanding of the Moon's geochemical history.
- The research team, led by Lars Borg of the Lawrence Livermore National Laboratory in California, used newly refined techniques to determine the age of a sample of FAN from the lunar rock collection at the Nasa Johnson Space Centre.
- The results are published in the journal Nature.