NASA’s deep space explorer Osiris-Rex flew on Monday to within a dozen miles of its destination, a skyscraper-sized asteroid believed to hold organic compounds fundamental to life as well as the potential to collide with Earth in about 150 years.
Launched in September 2016, Osiris-Rex embarked on NASA’s unprecedented seven-year mission to conduct a close-up survey of the asteroid Bennu, collect a sample from its surface and return that material to Earth for study.
Bennu, a rocky mass roughly a third of a mile wide and shaped like a giant acorn, orbits the sun at roughly the same distance as Earth and is thought to be rich in carbon-based organic molecules dating back to the earliest days of the solar system. Water, another vital component to the evolution of life, may also be trapped in the asteroid’s minerals.
Scientists believe that asteroids and comets crashing into early Earth delivered organic compounds and water that seeded the planet for life, and atomic-level analysis of samples from Bennu could help prove that theory.
But there is another, more existential reason to study Bennu.
Scientists estimate there is a one-in-2,700 chance of the asteroid slamming catastrophically into Earth 166 years from now. That probability ranks Bennu No. 2 on NASA’s catalog of 72 near-Earth objects potentially capable of hitting the planet.
