– A giant "city killer" asteroid, Asteroid 2008 OS7, is approaching Earth at 41,000 mph and 890 feet across.
– It is 7.4 times as far from Earth as the Moon and 1.77 million miles away
– The asteroid is too small and far away to be visible without a telescope, and will be about 10,000 times fainter than the faintest stars visible to the naked eye
– A livestream of the asteroid's flyby will be recorded by astrophysicist Gianluca Masi and his colleagues starting at 1 pm ET on YouTube
– Scientists have identified over 2,300 near-Earth objects, but NASA suspects there are many more out there that haven't been discovered
– If a giant asteroid were to hit Earth, it would take 5-10 years of warning to destroy or deflect it
– NASA's Near-Earth Object Surveyor mission, set to launch in September 2027, could expand the search for potential threats to Earth.