Key Facts

  • Classified as a Amor-class Asteroid
  • Comparable in size to the San Francisco Bay (4.90 km diameter)
  • Will pass within 7,473,703 km of Earth in 2057
  • Classified as a Near Earth Asteroid (NEA)
  • Classified as a Potentially Hazardous Asteroid (PHA)
  • See orbit simulation


Florence is a small asteroid whose orbit approaches the orbit of Earth but does not cross it. NASA JPL has classified Florence as a "Potentially Hazardous Asteroid" due to its predicted close pass(es) with Earth.

Florence orbits the sun every 859 days (2.35 years), coming as close as 1.02 AU and reaching as far as 2.52 AU from the sun. Florence is about 4.9 kilometers in diameter, making it larger than most asteroids, comparable in size to the San Francisco Bay.

The rotation of Florence has been observed. It completes a rotation on its axis every 2.36 days.

Florence's spectral type (Tholen) / S (SMASSII) indicates that it is likely to contain magnesium silicate and iron silicate.

Close Approaches

Florence's orbit is 0.04 AU from Earth's orbit at its closest point. This means that there is an wide berth between this asteroid and Earth at all times.

Florence has 4 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
Sept. 2, 2057 7,473,703 13.472
Sept. 11, 2097 23,312,843 12.991
Aug. 27, 2130 13,011,989 14.604
Aug. 28, 2170 11,687,810 14.496

Images and Observations

Florence's orbit is determined by observations dating back to March 9, 1979. It was last officially observed on July 5, 2019. The IAU Minor Planet Center records 4,596 observations used to determine its orbit.

Accessibility and Exploration

This asteroid is not considered a viable target for human exploration by the NHATS study.

Similar Objects

These objects have orbits that share similar characteristics to the orbit of Florence:



   or view a random object

Orbital Elements

  • Epoch: 2458600.5 JD
  • Semi-major axis: 1.76888951887 AU
  • Eccentricity: 0.423060108011
  • Inclination: 22.1423942138°
  • Longitude of Ascending Node: 336.080443752°
  • Argument of Periapsis: 27.8412197466°
  • Mean Anomaly: 242.872076077°

Physical Characteristics

  • Diameter: 4.90000 km
  • Magnitude: 14.0
  • Albedo: 0.231
  • Spectral type (SMASS): S

Derived Characteristics

  • Orbit Period: 859 days (2.35 years)
  • Avg. Orbit Speed: 22.39 km/s
  • Aphelion Distance: 2.52 AU
  • Perihelion Distance: 1.02 AU
  • Rotation Period: 2.36 days
  • Approx. Composition: magnesium silicate and iron silicate.

Size Comparison

Orbit Simulation

Sky Map

The position of Florence is indicated by a ◯ pink circle. Note that the object may not be in your current field of view. Use the controls below to adjust position, location, and time.