A new cosmic growth chart created by scientists of the Milky Way galaxy that we call home sheds light on how the galaxy evolved over time.

Using data from the Sloan Digital Sky Survey and a technique to help them determine the true age of stars, they found that red giant stars that were as old as 13 billion years old — about as old as the universe itself — were near the center of the galaxy while the younger stars of about 1 billion years old sat around the edge of the galaxy, according to a Discovery news report.

The findings were made by researchers at the Max Planck Institute for Astronomy in Germany and were presented at the American Astronomical Society meeting in Florida.

It’s a fascinating study that helps scientists learn more about how our galaxy formed, particularly by looking at how the ages change depending on where in the galaxy you are.

Melissa Ness, an astronomer at Planck who worked on the study, said she and her colleagues studied the chemistry of stars and used optical data from NASA’s Kepler space telescope to create a model to determine a star’s true age. A new technique involves looking at the ratio of carbon to nitrogen to determine the star’s age. The older red giant stars have the highest ratio of carbon to nitrogen, whereas younger stars have the lowest.

Obviously, the scientists couldn’t study all the stars, but a sample of 2,000 stars was more than enough to get the picture and then use a computer model to calculate the ages of 70,000 red giant stars.

More research will be needed, but it’s an exciting development that could help scientists learn a lot more about our Milky Way galaxy.