For the second time ever, humanity has brought asteroid samples down to Earth. A small capsule bearing pristine pieces of the near-Earth asteroid Ryugu touched down early this afternoon (Dec. 5) within the remote and rugged Woomera Prohibited Area, about 310 miles (500 kilometers) northwest of the South Australian capital of Adelaide. The samples were snagged millions of miles from Earth by Japan’s Hayabusa2 mission, which studied the 3,000-foot-wide (900 meters) Ryugu up close from June 2018 to November 2019.
Hayabusa2’s predecessor was the first to haul space-rock samples home, delivering pieces of the stony asteroid Itokawa in 2010. But the original Hayabusa (Japanese for “peregrine falcon”) returned less than 1 milligram of material. Hayabusa2’s bounty is expected to exceed 100 mg (0.0035 ounces), and its samples come from a very different kind of asteroid — a primitive “C-type” space rock rich in water and carbon-containing organic compounds. “The materials that formed the Earth, its oceans and life were present in the primordial cloud from which our solar system formed. In the early solar system, these materials were in contact and able to chemically interact within the same parent objects,” Japan Aerospace Exploration Agency (JAXA) officials wrote in an overview of Hayabusa2. “These interactions are retained even today in primitive bodies (C-type asteroids), so returning samples from these bodies for analysis will elucidate the origins and evolution of the solar system and the building blocks of life,” they added.