[21] Florence is classified as a potentially hazardous object because its minimum orbit intersection distance (MOID ≤ 0.05 AU) indicates that it has the potential to make close approaches to the Earth, and because measurements of its absolute magnitude (H ≤ 22) suggest that it is large enough to create serious damage were it to impact.

They probably formed as loose material spun away from the main body as its rotation accelerated due to the YORP effect.

On 1 September 2017, Florence passed[update] 0.047237 AU (7,066,600 km; 4,391,000 mi) from Earth, approximately eighteen times the average distance of the Moon.

[23] As seen from Earth, it brightened to apparent magnitude 8.5, and was visible in small telescopes for several nights as it moved south to north through the constellations Piscis Austrinus, Capricornus, Aquarius, and Delphinus.

[28] During the flyby, scientists studied Florence using the Arecibo Observatory and the Goldstone Deep Space Communications Complex, and discovered that it has two moons.