Geologists use radiometric dating to estimate how long ago rocks formed, and to infer the ages of fossils contained within those rocks. Radioactive elements decay The universe is full of naturally occurring radioactive elements. Radioactive atoms are inherently unstable; over time, radioactive "parent atoms" decay into stable "daughter atoms. When molten rock cools, forming what are called igneous rocks, radioactive atoms are trapped inside.
Radioactive Dating Age Of Fossils
D: Carbon Dating and Estimating Fossil Age - Biology LibreTexts
These findings suggest that the Moon was formed roughly 60 million years after the Solar System first formed, making it up to million years older than previous estimates. The impact that formed the Moon could have been large enough to wipe out any living thing on Earth, so knowing when that collision occurred is important if we hope to understand the evolution of our own planet, and when early life took root here. And the new research suggests that it happened earlier in the timeline of the Solar System than we thought - just 60 million years after our star system's birth, compared to previous estimates of to million years afterwards. To come up with the new lunar age estimate, the team analysed Moon rocks taken from the lunar surface during the Apollo 14 mission. The reason we've never been able to accurately date the age of the Moon in the past is that there's very few well-preserved Moon rocks left on its surface. So instead of trying to find chunks of rock that had been there since the early days, the team instead turned to zircon - a mineral that would have formed as the Moon was cooling from its fresh, molten state into the rocky satellite we see today.
Radioactive atoms called isotopes will decay into different kinds of atoms at a steady and constant rate. We can measure this rate. We express this in terms of 'half-life. This means that after million years a rock that had an initial quantity of uranium and no lead will have decayed to become half uranium half lead. Uranium decays to lead with a half-life of 4.
Planet Earth doesn't have a birth certificate to record its formation, which means scientists spent hundreds of years struggling to determine the age of the planet. So, just how old is Earth? By dating the rocks in Earth's ever-changing crust, as well as the rocks in Earth's neighbors, such as the moon and visiting meteorites, scientists have calculated that Earth is 4. Related: How Big is Earth?