A 2,000-foot-long asteroid, almost twice the size of the Rose Bowl, will zip safely past Earth on Wednesday at a distance of about 1.1 million miles, about 4.6 times the distance from Earth to the moon. While several small asteroids pass within this distance of Earth a few times a week, this is the closest by any known asteroid of this size or bigger in 13 years -- since asteroid Toutatis in 2004, according to the space agency. The flyby should also be visible with amateur telescopes, beginning in the early morning hours on Wednesday and then again that night, according to EarthSky.org. The next known encounter of an asteroid of about this size will occur in 2027 when the 800m-wide (half-mile-wide) asteroid 1999 AN10 will fly by at one lunar distance, about 380,000 km (236,000 miles). “The closest it’s going to be to the Earth is more than a million miles away.”

It's the closest this asteroid has come to Earth for at least the past 400 years and will be its closest approach for at least the next 500 years.
2014 JO25, a near-Earth asteroid discovered by the Catalina Sky Survey in May 2014, passes within 1.8 million kilometers of the planet, the largest such asteroid to transit close to Earth since 2004.