Our Milky Way galaxy is not very blended.

A new study shows that our galaxy is not as mixed as scientists sometimes think.

In particular, this new research focuses on the distribution of what astronomers think are metals---what is just each element outside of hydrogen and helium, even when those elements are gases. In the new work, scientists used the Hubble Space Telescope and the Very Large Telescope in Chile to map the metal in dust across the Milky Way in hopes of improving models describing the galaxy's history.

"At first, when the Milky Way has formed over 10 billion years ago, it had no metals," said Annalisa De Cia, an astronomer at the University of Geneva in Switzerland and principal author of the new research, says in a press release. "The stars gradually added to the environment with the metals they produced."

This enrichment occurs because, deep inside the core of a star, the atoms break to slowly form heavier and heavier types of matter, even though iron. Not all stars explode when they run out of the material that fuels that process, but the stars that do go boom toss all those metals out into their cosmic neighborhoods, where, theoretically, the metals can mix in with the rest of the Milky Way.

And traditionally, scientific models have assumed that the mixing process is very efficient, depending on the statement. The new observations, which targeted dust from almost 25 different stars, suggest that this may not be the case and that there are significant local differences in metal levels.

As such, scientists may have to reassess their understanding of the history of the Milky Way, the researchers said.

The research is set out in a document released on Wednesday (Sept. 8) in the journal Nature.