Chunk of Asteroid That Could Take Chunk Out of Earth Nears

There's a 1 in 2,700 chance that an asteroid known for its close flybys of Earth could smack into the planet in the next 160 years or so, which isn't very reassuring. NASA hopes, however, that the upcoming conclusion of a seven-year mission to retrieve samples from the near-Earth asteroid Bennu—about one-third of a mile in diameter, or roughly the size of the Empire State Building—will provide insight to lower the 0.037% chance of an impact with Earth in September 2182. The carbon-rich, diamond-shaped asteroid first discovered in 1999 passes close to Earth every six years, but it may eventually get too close. "The potential aftermath of its predicted collision with Earth could equate to the explosive energy of 22 atomic bombs," per Earth.com.

In 2016, NASA sent a spacecraft to explore Bennu. The Origins, Spectral Interpretation, Resource Identification, Security-Regolith Explorer (OSIRIS-REx) mapped Bennu's surface and led to better understanding of its geology and rotation. It also grabbed samples—so much material, in fact, that it had difficulty closing the lid on the sample container, and some material is likely to have floated off into space. The remaining 250 grams—the largest sample ever extracted from space, per Earth.com—is expected to land in Utah's Great Salt Lake Desert on Sunday in a livestreamed event. OSIRIS-REx, some 1.8 million miles from Earth as of Tuesday but hurtling this way at 14,000mph, will drop a small capsule whose descent will be slowed by parachutes, per Space.com.

"It feels very much like the last few miles of a marathon, with a confluence of emotions like pride and joy coexisting with a determined focus to complete the race well," says OSIRIS-REx project manager Rich Burns, per Space.com. The samples are not only crucial to better understanding potential asteroid threats. "Pristine material from asteroid Bennu will help shed light on the formation of our solar system 4.5 billion years ago and perhaps even on how life on Earth began," says Nicola Fox, an associate administrator of NASA's Science Mission Directorate. According to NASA, Bennu formed in the first 10 million years of our solar system's formation and could contain organic molecules that form the basis of all known life. (More asteroid stories.)