Whats in an Isotope Quite a LotScientists develop an new chronometer via Manganese-53, that can tell how many million years ago, an rock sample was exposed to the open sky. It works, because cosmic rays from space, can change minute amounts of iron into Manganese-53.
This amazing process, will allow you to dig up rocks, that have been buried underground for millions of years, and determine the last time they were exposed to air and sky!
It will work in a time frame going back 10 to 15 million years.
From the article:
"Whenever the first rock samples come back from Mars, this could be the prime tool for understanding when water stopped flowing across the planet surface," said Schaefer.