Nucleocosmochronology

Nucleocosmochronology is a way to measure how old stars, planets, and other objects in space are. It measures the amount of a special element, uranium, that is present in the object. Scientists know that over time, the uranium in those objects breaks down into other kinds of elements, so the more uranium there is, the younger the object is. To measure this, scientists look for something called a half-life-the amount of time it takes for half of the uranium to break down. By studying the age of the object and the amount of uranium in it, scientists can estimate how old it is.