“Birthdate” of the moon needs to be corrected

According to the latest analyses, the moon is between 80 and 180 million years older than previously thought. The age of most rock samples from the moon’s surface reflects the cooling of this magma and not the formation of the moon, the researchers said in the journal ‘Nature’. Shortly after the formation of the primordial Earth, about 4.5 billion years ago, another enormous crash occurred in the solar system: the Mars-sized celestial body Theia collided with the primordial Earth. The collision catapulted large amounts of glowing rock from the crust and mantle of the two celestial bodies into space – the moon was formed from these remnants of the planetary catastrophe.

But when exactly did this happen? Rock samples brought to Earth by the Apollo astronauts and a series of unmanned missions indicated an age of 4.35 billion years for the cooling of the moon’s surface. Therefore, the age of the Earth’s satellite was also previously taken into account. But the researchers also found crystalline inclusions in the moon rock, called zircons, that were older. This raised doubts about the supposed age of the moon.

“Rejuvenation” of the surface by magma
Francis Nimmo of the University of California, Thorsten Kleine of the Max Planck Institute for Solar System Research and Alessandro Morbidelli of Sorbonne University now present a solution to the dilemma. The newly formed moon initially moved along a highly elliptical path, very close to Earth. Earth’s satellite went through a phase of very strong tidal forces that heated its interior, transporting magma to the surface and thus causing an apparent rejuvenation. The conclusion: the moon could even be 4.53 billion years old!