An asteroid that is about 150 feet in diameter is expected to fly by Earth early Friday afternoon.
While NASA says there's no chance that asteroid 2012 DA14 will hit Earth, the asteroid is expected to pass between Earth and its ring of geosynchronous weather and communications satellites.
"The flyby of asteroid 2012 DA14 is the closest ever predicted Earth approach for an object this large," according to the NASA website. "Scientists at NASA's Near-Earth Object Program Office in Pasadena, CA, estimate that an asteroid the size of 2012 DA14 flies this close every 40 years on average and that one will impact Earth, on average, about once in every 1,200 years."
At its closest approach, asteroid 2012 DA14 will be about 17,200 miles from Earth, NASA says.
The asteroid is expected to fly by Earth at about 1:24 p.m. Central time, according to the Adler Planetarium.
NASA notes that the asteroid will be too dim to be seen with the naked eye. It will be best seen from parts of Europe, Africa and Asia.