Since the planet Earth doesn't have a birth certificate to record its formation, scientists have spent hundreds of years struggling to determine the age of the planet. By dating the rocks in the ever-changing crust, as well as neighbors such as the moon and visiting meteorites, scientists have calculated that Earth is 4.54 billion years old, with an error range of 50 million years.
How old are your rocks?
Several attempts to scientifically date the planet have occurred over the past 400 years.
Scientists attempted to predict the age based on changing sea levels, the time it took for Earth or the sun to cool to present temperatures, and the salinity of the ocean. As science progressed, these methods were proven to be unreliable; for instance, the rise and fall of the ocean was shown to be an ever-changing process rather than a gradually declining one.
In an effort to calculate the age of the planet, scientists turned to the rocks that cover its surface. However, because plate tectonics constantly changes and revamps the crust, the first rocks have long since been recycled, melted down and reformed into new outcrops.
/Space.Com/