## How do we determine the age of a planet?

The best estimate for Earths age is based on radiometric dating of fragments from the Canyon Diablo iron meteorite. From the fragments, scientists calculated the relative abundances of elements that formed as radioactive uranium decayed over billions of years.

## Which dating technique has been used to date the age of the Earth?

Radiometric dating Radiometric dating, which relies on the predictable decay of radioactive isotopes of carbon, uranium, potassium, and other elements, provides accurate age estimates for events back to the formation of Earth more than 4.5 billion years ago.

## How do we determine the age of an asteroid?

Scientists typically determine the age of a rock or meteorite by using the isochron method. For purposes of illustration, consider the rubidium-strontium decay system. In this system, the radioactive parent rubidium-87 (87Rb) decays to the stable daughter isotope strontium-87 (87Sr).