Key Facts

  • Categorized as a Aten-class Asteroid
  • Comparable in size to a school bus or smaller
  • Will pass within 4,065,445 km of Earth in 2021
  • Classified as a Near Earth Asteroid (NEA)
  • Not a Potentially Hazardous Object
  • See orbit simulation

Overview

1998 SD9 is a very small asteroid whose orbit could bring it in close proximity to Earth. NASA JPL has classified 1998 SD9 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.

1998 SD9 orbits the sun every 215 days (0.59 years), coming as close as 0.35 AU and reaching as far as 1.06 AU from the sun. Based on its brightness and the way it reflects light, 1998 SD9 is probably between 0.044 to 0.099 kilometers in diameter, making it a small to average asteroid, very roughly comparable in size to a school bus or smaller.

Close Approaches

1998 SD9's orbit is 0.01 AU from Earth's orbit at its closest point. This means that its orbit is relatively close to Earth's orbit.

1998 SD9 has 38 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
Oct. 6, 2021 4,065,445 10.817
Aug. 25, 2028 8,989,398 12.470
Oct. 1, 2031 4,996,416 9.754
Aug. 26, 2038 21,196,052 15.296
Sept. 15, 2041 7,827,062 9.318
Oct. 9, 2044 20,039,533 14.788
Aug. 31, 2051 2,012,693 10.259
Oct. 8, 2054 6,841,237 11.598
Aug. 27, 2061 4,003,644 11.344
Oct. 4, 2064 3,697,894 10.350
Aug. 26, 2071 14,633,594 13.789
Sept. 24, 2074 7,332,162 9.403
Oct. 8, 2077 27,086,800 16.461
Sept. 5, 2084 5,474,660 9.635
Oct. 10, 2087 11,375,377 12.711
Aug. 27, 2094 4,721,414 11.523
Oct. 2, 2097 4,949,570 9.854
Aug. 27, 2104 28,185,950 16.971
Sept. 6, 2107 5,064,829 9.687
Oct. 10, 2110 8,022,667 11.911
Aug. 27, 2117 11,038,755 12.978
Sept. 26, 2120 7,092,143 9.450
Oct. 10, 2123 27,032,580 16.450
Sept. 4, 2130 4,280,890 9.825
Oct. 10, 2133 9,149,953 12.152
Aug. 28, 2140 3,073,696 11.168
Oct. 6, 2143 4,011,459 10.253
Aug. 27, 2150 19,264,846 14.880
Sept. 18, 2153 8,003,841 9.332
Oct. 10, 2156 19,840,749 14.741
Sept. 1, 2163 1,381,321 10.365
Oct. 10, 2166 8,319,469 11.921
Aug. 31, 2173 1,142,932 10.402
Oct. 10, 2176 13,512,524 13.187
Aug. 28, 2180 29,898,413 17.371
Sept. 19, 2183 7,778,002 9.360
Aug. 27, 2190 11,558,189 13.088
Oct. 5, 2193 4,180,388 10.280

Images and Observations

1998 SD9's orbit is determined by observations dating back to Sept. 18, 1998. It was last officially observed on Sept. 15, 2018. The IAU Minor Planet Center records 150 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 1998 SD9:

References

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Orbital Elements

  • Epoch: 2459396.5 JD
  • Semi-major axis: 0.7028 AU
  • Eccentricity: 0.5041
  • Inclination: 3.02°
  • Longitude of Ascending Node: 166.14°
  • Argument of Periapsis: 7.27°
  • Mean Anomaly: 68.14°

Physical Characteristics

  • Diameter: ~0.057 km
  • Magnitude: 23.9

Derived Characteristics

  • Orbit Period: 215 days (0.59 years)
  • Avg. Orbit Speed: 35.56 km/s
  • Aphelion Distance: 1.06 AU
  • Perihelion Distance: 0.35 AU

Map Comparison

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Orbit Simulation

Sky Map

The position of 1998 SD9 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 below comparison is an artistic rendering that uses available data on the diameter of 1998 SD9 to create an approximate landscape rendering with New York City in the background. This approximation is built for full-resolution desktop browsers. Shape, color, and texture of asteroid are imagined.