NASA spacecraft will deliver asteroid sample

Planet Earth is about to receive a special delivery — the biggest sample yet from an asteroid. A NASA spacecraft will fly by Earth on Sunday and drop off what is expected to be at least a cupful of rubble it grabbed from the asteroid Bennu, closing out a seven-year quest. The sample capsule will parachute into the Utah desert as its mothership, the Osiris-Rex spacecraft, zooms off for an encounter with another asteroid. Scientists anticipate getting about a half pound (250 grams) of pebbles and dust, much more than the teaspoon or so brought back by Japan from two other asteroids. No other country has fetched pieces of asteroids, preserved time capsules from the dawn of our solar system that can help explain how Earth — and life — came to be. Sunday’s landing concludes a 4 billion-mile (6.2-billion-kilometer) journey highlighted by the rendezvous with the carbon-rich Bennu, a unique pogo stick-style touchdown and sample grab, a jammed lid that sent some of the stash spilling into space, and now the return of NASA’s first asteroid samples. “I ask myself how many heart-pounding moments can you have in one lifetime because I feel like I might be hitting my limit,” said the University of Arizona’s Dante Lauretta, the mission’s lead scientist.