An asteroid that could one day cause significant damage to the Earth in the 22nd century is about to receive a modern-day visitor.
NASA is the final stages of preparing for the launch of OSIRIS-REx, an unmanned spacecraft with a mission to study a 1,600-foot-wide asteroid called Bennu. Once it leaves Earth's orbit, the OSIRIS-REx (Origins, Spectral Interpretation, Resource Identification, Security – Regolith Explorer) will spend two years cruising to Bennu and another two years meticulously mapping its surface. The true pièce de résistance, however, will occur in 2020, when OSIRIS will use a small vacuum-like device to suck up samples from Bennu before its return trip to Earth.
Like Comet 67, which is currently being investigated by the European Space Agency's Rosetta spacecraft, the asteroid Bennu may offer additional insights into the formation of our solar system.
"On planets like Earth, the original materials have been profoundly altered by geologic activity and chemical reactions with our atmosphere and water," said Edward Beshore, deputy principal investigator for OSIRIS-REx. "We think Bennu may be relatively unchanged, so this asteroid is like a time capsule for us to examine."
NASA's interest in Bennu also relates to its status as a potential Earth impactor, with a 1-in-2,700 chance of hitting the planet between the years 2175 to 2196. Were that to happen, scientists estimate Bennu's impact would be 4,000-5000 times more powerful than the Chelyabinsk meteor that dramatically exploded over Russia in 2013. While certainly not a world-threatening event (it's estimated that it would take an object 60 miles wide to completely wipe out life on Earth), Bennu's impact on an urban population center would likely be apocalyptic.
"If astronomers someday identify an asteroid that presents a significant impact hazard to Earth, the first step will be to gather more information about that asteroid," added Beshore. "Fortunately, the OSIRIS-REx mission will have given us the experience and tools needed to do the job."
Should all go according to plan, NASA plans on launching the OSIRIS-REx on Sept. 8.