The age of rocks is determined by radiometric dating, which looks at the proportion of two different isotopes in a sample. Radioactive isotopes break down in a predictable amount of time, enabling geologists to determine the age of a sample using equipment like this thermal ionization mass spectrometer.

What are the three methods for dating the earth?

I describe just three of these many approaches—annual layerings, geologic rates, and our most accurate and reliable method, isotopic age determinations or “radiometric dating.” When properly applied, all three approaches yield identical estimates of geologic events.

What is the scientifically accepted age of the Earth?

4.54 billion years old Earth is estimated to be 4.54 billion years old, plus or minus about 50 million years. Scientists have scoured the Earth searching for the oldest rocks to radiometrically date. In northwestern Canada, they discovered rocks about 4.03 billion years old.

How did life start?

How did non-living molecules that covered the young Earth combine to form the very first life form? Many scientists believe that RNA, or something similar to RNA, was the first molecule on Earth to self-replicate and begin the process of evolution that led to more advanced forms of life, including human beings.