ASTROGEOLOGY 5 (ADVANCED LEVEL)

THE AGE OF METEORITES

            Using radioactive materials present in meteorites especially in stony meteorites, geologists have determined the age of meteorites. Meteorites range in age. The oldest particles in a meteorite, calcium-aluminum-rich inclusions from carbonaceous chondrites, have been dated at 4.56 years old. 

-          Meteorites that originate from asteroids are all ~4.5 billion years old.

-          Meteorites that originate from the Moon range in age from 4.5 to 2.9 billion years old.

-          Meteorites that originate from Mars range in age from 4.5 billion years old to 200 million years old.

Importance of meteorites

            Meteorites are very accessible since they occasionally fall to the earth. So they help in understanding:

1)      Stellar evolution:

Some meteorites contain grains of dust (“stardust”) that were produced by stars before the formation of our Solar System.  Studies of these grains can increase our understanding of stars and their role in the universe.

2)      Age and composition of the Solar System:

We can estimate the age and bulk chemical composition of the Solar System and the order in which different components in meteorites – and the Solar System – formed, by measuring the amounts of various elements in meteorites.

3)      Solar System evolution:

In the ASU Center for Meteorite Studies, the analysis of different types of meteorites and their components in our cutting-edge research laboratories is leading to new knowledge of the earliest conditions in our Solar System, and determining the pathways to forming habitable worlds.

4)      Geologic history of Earth and the Moon:

Large meteorite impacts have shaped the face of our planet and the Moon through time. Many scientists believe that a very large impact was even responsible for the formation of the Moon.

5)      History of life:

Meteorites may have brought to Earth the chemicals necessary for the origin of life.  Large meteorite impacts, like the one ~65 million years ago that killed off the dinosaurs, may have lead to major extinctions that influenced the course of life on our planet.

(Web source: https://meteorites.asu.edu/meteorites/meteorite-facts)