Metals from space descend on Boulder, Colorado, at dusk and dawn - Ars Technica

And, like clockwork, a layer of sodium and other elements trickle down through the sky and hit the ground, a team of researchers at the University of Colorado-Boulder found.

These elements hail originally from space and, in various forms, hit the atmosphere before making their trek to the Earth's surface.

A decade ago, Xinzhao Chu, the lead author of the research, discovered these metal layers at the McMurdo research station in Antarctica.

This is the first time researchers have discovered a case where the layers drop at regular intervals.

While the lidar data from the region was taken a few years back, the team analyzed them last December and discovered our atmosphere's metal cycle.

According to Chu, studying these metal layers might also help scientists make better estimates about the amount of cosmic dust that reaches the Earth, though other methods would also be necessary.

According to Chu, studying these metals could also help researchers pick out planets that could harbor life.

Generally, when looking for other potentially life-sustaining planets, researchers look for qualities that are similar to Earth's.

The process Chu's team described is only possible because of the structure of Earth's atmosphere and magnetic fields.