NASA warns of 'close encounter' with gigantic near-Earth
NASA has confirmed that a large asteroid, known as Florence, will fly past Earth on September 1 at a distance of 4.4 million miles (7.0 million kilometers). That's roughly 18 times the distance to the moon and is close enough to categorise Florence as a near-Earth asteroid . It's also one of the largest rocks the space agency has ever detected since it began monitoring passing asteroids. The experts believe it is around 2.7 miles (4.4 kilometers) in size. While many known asteroids have passed by closer to Earth than Florence will on September 1, all of those were estimated to be smaller, said Paul Chodas, manager of NASA’s Center for Near-Earth Object Studies (CNEOS) at the agency's Jet Propulsion Laboratory in Pasadena, California. Florence is the largest asteroid to pass by our planet this close since the NASA program to detect and track near-Earth asteroids began.
Because of its size, NASA thinks Florence is an excellent target to test out its various asteroid observation technologies. Using radar arrays here on the ground, the space agency reckons it can capture pictures of Florence with surface details as small as 10m (30 feet). When these small, natural remnants of the formation of the solar system pass relatively close to Earth, deep space radar is a powerful technique for studying their sizes, shapes, rotation, surface features and roughness, and for more precise determination of their orbital path, explained NASA.