How old is planet Earth?

How old is planet Earth?

• A. 4.6 Billion Years
• B. 4.6 Million Years
• C. 6.0 Billion Years
• D. 3.0 Billion Years

Answer: (A)

Dating ancient rocks and meteorites relies on radiometric dating, which uses the predictable decay of radioactive isotopes to measure how long ago a mineral solidified. By examining isotopes such as uranium and lead in the oldest Earth minerals (like zircon) and the oldest Solar System material (meteorites and Moon rocks), scientists can pin down ages on the order of billions of years. The formation of the Sun and planets occurred about 4.6 billion years ago, and the dating results from meteorites and the oldest rocks align with that timing, giving Earth a best estimate near 4.6 billion years. So, a value around 4.6 billion years is the most consistent with the evidence. Numbers like 4.6 million years, 6.0 billion years, or 3.0 billion years don’t match the radiometric dating results and the Solar System’s formation timeline.

Dating ancient rocks and meteorites relies on radiometric dating, which uses the predictable decay of radioactive isotopes to measure how long ago a mineral solidified. By examining isotopes such as uranium and lead in the oldest Earth minerals (like zircon) and the oldest Solar System material (meteorites and Moon rocks), scientists can pin down ages on the order of billions of years. The formation of the Sun and planets occurred about 4.6 billion years ago, and the dating results from meteorites and the oldest rocks align with that timing, giving Earth a best estimate near 4.6 billion years. So, a value around 4.6 billion years is the most consistent with the evidence. Numbers like 4.6 million years, 6.0 billion years, or 3.0 billion years don’t match the radiometric dating results and the Solar System’s formation timeline.