A colossal "city killer" asteroid, measuring about 890 feet across, will make its closest approach to Earth on February 2. At a distance of 1.77 million miles, this is more than seven times farther than the moon. According to NASA's Jet Propulsion Laboratory, the potentially hazardous asteroid is the size of a football field and is traveling at a speed of 41,000 mph. Although too faint to be seen without a telescope, enthusiasts can watch the live event on YouTube, on the Virtual Telescope Project, at 1 p.m. ET. The asteroid, named 2008 OS7, orbits the sun every 962 days and is classified as "potentially hazardous" due to its size and proximity to Earth. NASA's upcoming Near-Earth Object Surveyor mission aims to enhance our ability to detect and monitor these threats