Key Facts

  • Categorized as a Aten-class Asteroid
  • Comparable in size to the Golden Gate Bridge (0.59 km diameter)
  • Will pass within 20,776,674 km of Earth in 2021
  • Classified as a Near Earth Asteroid (NEA)
  • Not a Potentially Hazardous Object
  • See orbit simulation

Overview

85953 (1999 FK21) is a small asteroid whose orbit could bring it in close proximity to Earth. NASA JPL has classified 1999 FK21 as a "Near Earth Asteroid" due to its orbit's proximity to Earth, but it is not considered potentially hazardous because computer simulations have not indicated any imminent likelihood of future collision.

1999 FK21 orbits the sun every 232 days (0.64 years), coming as close as 0.22 AU and reaching as far as 1.26 AU from the sun. Its orbit is highly elliptical. 1999 FK21 is about 0.6 kilometers in diameter, making it larger than ~97% of asteroids but small compared to large asteroids, comparable in size to the Golden Gate Bridge.

The rotation of 1999 FK21 has been observed. It completes a rotation on its axis every 28.08 hours.

1999 FK21's spectral type None (Tholen) / S (SMASSII) indicates that it is likely to contain and .

Close Approaches

1999 FK21's orbit is 0.07 AU from Earth's orbit at its closest point. This means that there is a wide berth between this asteroid and Earth at all times.

1999 FK21 has 44 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
Feb. 16, 2021 20,776,674 21.609
April 8, 2025 12,078,437 18.988
Feb. 16, 2028 18,552,599 19.435
April 7, 2032 11,295,183 20.839
Feb. 17, 2035 21,523,212 17.805
April 7, 2039 18,722,026 23.252
Feb. 20, 2042 27,402,231 16.716
April 4, 2046 29,562,897 25.991
April 1, 2051 28,830,084 16.415
April 6, 2058 21,459,525 17.104
Feb. 16, 2061 22,590,865 22.387
April 8, 2065 14,080,928 18.438
Feb. 16, 2068 18,537,473 20.143
April 8, 2072 10,753,144 20.117
Feb. 17, 2075 19,876,985 18.352
April 8, 2079 15,503,935 22.331
Feb. 19, 2082 25,077,930 17.016
April 6, 2086 25,172,054 24.893
April 4, 2098 24,568,856 16.768
Feb. 18, 2101 25,647,703 23.451
April 8, 2105 17,075,798 17.820
Feb. 18, 2108 19,537,733 21.091
April 9, 2112 11,592,980 19.305
Feb. 17, 2115 18,573,517 19.062
April 10, 2119 12,658,220 21.355
Feb. 19, 2122 22,529,695 17.493
April 8, 2126 20,613,108 23.704
Feb. 22, 2129 28,074,590 16.634
April 4, 2138 27,648,832 16.505
Feb. 20, 2141 29,447,616 24.627
April 7, 2145 20,376,506 17.268
Feb. 19, 2148 21,608,877 22.106
April 9, 2152 13,630,149 18.604
Feb. 18, 2155 18,164,969 19.835
April 10, 2159 11,251,464 20.510
Feb. 18, 2162 20,489,031 18.042
April 9, 2166 17,061,508 22.722
Feb. 21, 2169 25,737,663 16.901
April 6, 2173 27,145,671 25.345
April 6, 2185 22,944,142 16.943
Feb. 19, 2188 23,754,689 22.906
April 9, 2192 15,588,794 18.148
Feb. 18, 2195 18,422,344 20.453
April 10, 2199 11,153,451 19.960

Images and Observations

1999 FK21's orbit is determined by observations dating back to March 26, 1971. It was last officially observed on Feb. 4, 2022. The IAU Minor Planet Center records 1,276 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 1999 FK21:

References

Search

   or view a random object

Orbital Elements

  • Epoch: 2459800.5 JD
  • Semi-major axis: 0.7388 AU
  • Eccentricity: 0.7031
  • Inclination: 12.61°
  • Longitude of Ascending Node: 180.47°
  • Argument of Periapsis: 172.4°
  • Mean Anomaly: 196.48°

Physical Characteristics

  • Diameter: 0.59000 km
  • Magnitude: 18.21
  • Albedo: 0.32
  • Spectral type (SMASS): S

Derived Characteristics

  • Orbit Period: 232 days (0.64 years)
  • Avg. Orbit Speed: 34.64 km/s
  • Aphelion Distance: 1.26 AU
  • Perihelion Distance: 0.22 AU
  • Rotation Period: 28.08 hours
  • Approx. Composition: and .

Map Comparison

Click to load map

Orbit Simulation

Sky Map

The position of 85953 (1999 FK21) 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.

Size Rendering

The above comparison is an artistic rendering that uses available data on the diameter of 1999 FK21 to create an approximate landscape rendering with Mount Everest in the background. This approximation is built for full-resolution desktop browsers. Shape, color, and texture of asteroid are imagined.