'Potentially Hazardous' Asteroid , to Zoom Past Earth.br 'Newsweek' reports that a massive "potentially br hazardous asteroid," approximately the size of br the Empire State Building, is due to pass the Earth.br According to NASA's Center for Near-Earth br Object Studies (CNEOS), the asteroid is br estimated to be between 690 and 1,570 feet across.br The large asteroid will pass the Earth at a distance of br just about 0.01908 astronomical units, equal to about br 1.77 million miles, a close call in astronomical distances.br The asteroid will make its flyby br on February 2, passing the Earth at br an estimated 40,700 miles per hour.br 'Newsweek' reports that asteroids are rocks left br over from the formation of our solar system, which br can range in size from fairly small to enormous. .br Ceres, the largest known asteroid, br is a staggering 600 miles across.br The asteroid on the way to pass Earth is classified as br both a "Near Earth Object" (NEO) and a "Potentially br Hazardous Asteroid" (PHA) due to its size and trajectory.br There are 31,000 known solar system br objects that are considered NEOs, br while NASA is aware of 2,350 PHAs.br A potentially hazardous asteroid (PHA) br is one that has an orbit intersecting br the Earth's orbit around the Sun by br less than 0.05 astronomical unitsbr (1 AU is the distance to the Sun), br that's just over 4.5 million miles. , Martin Barstow, professor of astrophysics and space science br at the University of Leicester in the U.K., via 'Newsweek'.br It also has to have an absolute br brightness of 22.0 or less (lower br values of the magnitude are brighter = br larger objects), ie. an asteroid (or comet) br that would cause significant regional br damage if it hit the Earth. , Martin Barstow, professor of astrophysics and space science br at the University of Leicester in the U.K., via 'Newsweek'.br Not all NEOs are br potentially hazardous, but br all hazardous objects are NEOs, Martin Barstow, professor of astrophysics and space science br at the University of Leicester in the U.K.