Just days after an asteroid the size of the Empire State Building flew past Earth, another "potentially hazardous" space rock will do the same. Asteroid 2019 OU1 will safely pass by Earth on Aug. 28, coming within 639,000 miles or 0.00687 astronomical units of the planet. At an estimated diameter of 71 to 160 meters (233 to 524 feet), 2019 OU1 has sparked comparisons to the 555-foot tall Washington Monument. 2019 OU1 is also hurtling through space at roughly 42,650 feet per second, according to data compiled by NASA. The space rock is known as a near-Earth object (NEO) and "potentially hazardous" NEOs are defined as space objects that come within 0.05 astronomical units and measure more than 460 feet in diameter, according to NASA. According to a 2018 report put together by Planetary.org, there are more than 18,000 NEOs. You can read more about Asteroid 2019 OU1 here, at: