The oldest object known to humans fell from the sky on Feb. 8, 1969, with the furor of a divine omen. The blue-white fireball streaked over northern Mexico at 1:05 a.m., ending with a staccato of booms heard from hundreds of miles away. A small asteroid had struck Earth’s atmosphere and exploded — raining thousands of fragments over the desert. NASA dispatched scientists to the site, and days later they returned with 13 fragments of the space rock. Each was coated with a smooth, gla…