Early on Sunday morning, the skies above a secluded military complex in central Australia will be brightened by a fireball plummeting to Earth. It will be a flamboyant homecoming for the sample return capsule from Hayabusa2, a Japanese spacecraft launched almost exactly six years ago on a mission to shoot an ancient asteroid and steal some of its dirt. If the capsule survives its fiery descent, its payload of pristine space rock will help scientists understand the earliest days of our solar system, shed light on the mysterious origins of meteorites, and may even provide clues about the emergence of life on Earth.
By the time it lands under parachute in the Australian outback, the sample will have traveled more than 180 million miles from Ryugu, a diamond-shaped asteroid orbiting the sun between Earth and Mars. Scientists believe that Ryugu broke off from a larger parent body only a few