Large asteroid will safely fly by Earth September 1
A massive asteroid will flyby Earth later this month.

By Laurel Kornfeld | 5 hours ago

A 2.7-mile wide asteroid, the largest near-Earth object to fly close to our planet since such objects were discovered approximately 100 years ago, will make its closest approach to Earth on Friday, September 1.

Nicknamed "Florence," the object poses no threat to our planet, and will come no closer than 4.4 million miles, or approximately 18 times the Earth-Moon distance, which averages 238,855 miles.

Because of its large size and relatively close passage to Earth, the asteroid makes an ideal target for NASA to measure with radio telescopes.

With a visible magnitude of 9, Florence will be an easy target for anyone with a telescope, who, starting on August 27, will be able to see it pass through several constellations, including Piscis Austrinus, Capricornus, Aquarius, and Delphinus, noted Rudiger Jehn of the European Space Agency (ESA).

Initially dubbed Asteroid 1981 ET3, Florence was discovered in October 1981 at Siding Spring Observatory in Australia. It was subsequently named Florence 3122 in honor of nursing pioneer Florence Nightingale.

Its size was determined by scientists studying it with the Spitzer Space Telescope and with NASA's Near-Earth Object Wide-field Survey Explorer (NEOWISE) mission, a project that measures the sizes of asteroids and comets near the Earth.

"While many known asteroids have passed by closer to Earth than Florence will on September 1, all of those were estimated to be smaller," explained Paul Chodas, who manages NASA's Center for Near-Earth Object Studies.

A total of 1,826 asteroids and comets are being tracked by NASA as Potentially Hazardous Asteroids. This means they could at some point pose a threat of impacting our planet.

Although a few of those are larger than Florence, none has come as close to Earth as it will later this week.

Earlier this year, asteroid AG13, with a diameter between 36 and 111 feet,managed to come within half the Earth-Moon distance, surprising astronomers, who had no advance warning of its passage.

A similarly-sized asteroid, 2012 TC4, will harmlessly come within one-quarter of the Earth-Moon distance on October 12.

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