"The 2017 encounter is the closest by this asteroid since 1890 and the closest it will ever be until after 2500", NASA says.
NASA says in a news release that Florence is the largest asteroid to pass our planet since the USA space agency started detecting and tracking "near-Earth" asteroids. This impact also destroyed three-quarters of the plant and animal species on Earth, hence why organizations like NASA's Center for Near-Earth Object Studies (CNEOS) is in he habit of tracking the larger NEAs. That is why radar imaging is planned at NASA's Goldstone Solar System Radar in California and at the National Science Foundation's Arecibo Observatory in Puerto Rico.
The asteroid will be seven million km away from earth which is 18 times the distance between earth and moon. If that doesn't sound impressive, consider its size: At 2.7 miles, Florence is the largest asteroid to pass Earth since NASA began tracking near-Earth asteroids.
"While many known asteroids have passed by closer to Earth than Florence will on September 1, all of those were estimated to be smaller". But with a small telescope, stargazers can catch Florence several nights between late August and early September, near the Capricornus and Aquarius constellations, according to JPL. "If Florence has a satellite, then our chances of detecting it are excellent, and if so, then we plan to measure its motion to estimate the orbital parameters, mass, and density of the system", NASA said.
The asteroid was first spotted in March 1981 by astronomer Schelte "Bobby" Bus at Siding Spring Observatory in Australia. The scientific interest in comets and asteroids is due largely to their status as the relatively unchanged remnant debris from the solar system formation process some 4.6 billion years ago.
The US space agency is hoping that radar will successfully reveal the exact size of the asteroid, as well as interesting nooks and crannies on the surface.
In October this year, an even closer encounter is expected when asteroid 2012 TC4 will come within just 13 percent of the distance between the Earth and the moon-about 31,000 miles. The asteroid is named after nurse and social reformer Florence Nightingale.
The relief though is that this rock is much smaller, measuring only 15 m (49 ft) across.