Asteroid 3122 Florence, a large near-Earth asteroid, will pass by Earth next Friday, at a distance of seven million kilometers, or about 18 Earth-Moon distances; NASA announced on August 18.
Surprisingly, Florence is among the largest near-Earth asteroids that are several kilometers in size; measurements from NASA’s Spitzer Space Telescope and NEOWISE mission indicate it’s about 4.4km 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 (JPL) 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,” Chodas told DC Agle of JPL.
Fortunately, this relatively close encounter provides an opportunity for scientists to study this asteroid up close. Astronomers believe that Florence will benefit us perfectly in ground-based radar observations.
NASA plans for its radar imaging at the Goldstone Solar System Radar in California; and at the National Science Foundation’s Arecibo Observatory in Puerto Rico.
Opportunely, the resulting radar images will show the real size of Florence. It could reveal surface details as small as ten meters.
Animation by NASA of Florence’s flyby next Friday.
I’m Watching You
In fact, Schelte “Bobby” Bus was the first to discover Florence at Siding Spring Observatory in Australia in March 1981. In addition, he named it in honor of Florence Nightingale (1820-1910), the founder of modern nursing.
Friday’s encounter is the closest by this asteroid since 1890 and the closest it will ever be until after 2500, Laurie Cantillo and Dwayne Brown from NASA Headquarters, Washington reported.
Gladly, Florence currently has a ninth magnitude brightness. This makes it visible in small telescopes for several nights. You can see it moving through the constellations Piscis Austrinus, Capricornus, Aquarius and Delphinus.
Remarkably, the visitor asteroid is of a stony type from the Amor group. In fact, it orbits the Sun at a distance of 1.0–2.5 AU every 859 days. Its orbit has an eccentricity of 0.42 and an inclination of 22° with respect to the ecliptic.
Unfortunately, astronomers have classified it as a potentially hazardous asteroid (PHA) because of its absolute magnitude (H ≤ 22) and its minimum orbit intersection distance (MOID ≤ 0.05 AU).
Beneficially, radar has been used to observe hundreds of asteroids. When these 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.
JPL manages and operates NASA’s Deep Space Network, including the Goldstone Solar System Radar, and hosts CNEOS for NASA’s Near-Earth Object Observations Program, an element of the Planetary Defense Coordination Office within the agency’s Science Mission Directorate.
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Actual scale of distance between Florence and Earth next Friday, 1st September 2017.