It's the kind of asteroid that some scientists worry about, and it's coming relatively close to Earth on Saturday. Thankfully, it is expected to remain a safe distance away.
Named 2002 NN4, the asteroid is more than 1,000 feet across and will swing by near enough to make it onto NASA's "close approach" list, which documents near-Earth objects and the dates they approach our planet.
It's traveling at more than 20,000 mph — so the damage 2002 NN4 could inflict on earth is catastrophic, Derek Buzasi, professor of physics at Florida Gulf Coast University, told USA TODAY. He said 2002 NN4 is bigger than roughly 90% of asteroids and likened it to a football stadium.
Thankfully, this particular space rock is predicted to stay more than 3 million miles away — or 13 times farther from us than the Moon, NASA said in an emailed statement to USA TODAY. The path of the asteroid is expected to vary by only around 125 miles.
"In short, 2002 NN4 is a very well-known asteroid with a known orbit that will pass Earth at a (very) safe distance," wrote Ian J. O'Neill of NASA's Jet Propulsion Laboratory.
Asteroids like 2002 NN4 cause concern because of their potential impact on Earth. While smaller space rocks are difficult to track, they are unlikely to cause major damage. Larger asteroids are fairly well understood and tracked, Buzasi said.
While the path of 2002 NN4 is well known, some asteroids its size may have not yet been discovered, Buzasi said. Those are the ones experts worry about.