Dr. Duprat and his colleagues drilled into the snow and in the cores they retrieved found two particles, each 100th of a micron in size, that were exactly what they were looking for.

Image Clean snow is pulled from a trench near the Concordia Research Station. Credit... J. Duprat CSNSM-CNRS

Because of the depth at which the materials were found, about 12 feet, they were able to estimate that they were deposited into the Earth from 1955 to 1970. By studying the molecules and minerals in the particles, which, though tiny, each contain enough material to analyze, the researchers were able to determine that the sediments were formed in our solar system billions of years ago. Their results are published in the May 7 Journal of Science.

To determine the particles’ origins, the scientists looked at their chemical makeup. They had larger amounts of carbon and deuterium, a form of hydrogen, than anything found on Earth, Dr. Duprat said.

He and his colleagues further analyzed the chemical makeup, and found that the compositions of the particles were similar to remnants from comets, including Halley’s Comet.

The grains may be as old as the sun, he said.

Future research might reveal more about exactly how these particles formed, and how they arrived on earth. But that will require more trips to the Concordia Research Station in Antarctica, and more samples.