In December 2020, Japan's Hayabusa2 spacecraft swung by Earth to drop off a cache of rock samples taken from a near-Earth asteroid called Ryugu. Asteroids like Ryugu are thought to represent the ancient building blocks of the solar system, and scientists have been eager to get a closer look at the returned samples.

Last week, the Japanese Aerospace Exploration Agency shipped one of the samples—a millimeter-sized fragment from the asteroid's surface—to the laboratory of Brown University planetary scientist Ralph Milliken for analysis. Milliken's lab is one of the first in the U.S. to examine a Ryugu sample so far.

Milliken and Takahiro Hiroi, a senior research scientist at Brown, are members of the Hayabusa2 mission's science team.