On Sunday, September 24 at approximately 10:42 EST, a NASA mission known as OSIRIS-REx will return to Earth after having collected samples from an asteroid named Bennu. Some experts also predict that 159 years from now, there's a good chance Bennu could collide with Earth.
Such an event would be extremely unlucky for life on this planet, with potential for catastrophic destruction. Bennu is roughly 1,640 feet (500 meters) wide — or as large as the Empire State Building — and upon impact it would release 1,200 megatons of energy, or 24 times as much as the most powerful nuclear weapon built so far. This would equate to roughly the energy produced by 22 atomic bombs.
What do we know for sure about this celestial behemoth that is barreling toward Earth, conjuring up images from sci-fi disaster movies like "Deep Impact" and "Armageddon" as it does so? Here's everything we know so far about Bennu and what we hope to learn once a sample of it (ideally) returns on Sunday.
