85938 (1999 DJ4)

Small Apollo-class Asteroid

Near-Earth Potentially Hazardous
Space Reference » Apollo-class Asteroids » 85938 (1999 DJ4)

Key Facts

  • Categorized as a Apollo-class Asteroid
  • Comparable in size to the Golden Gate Bridge
  • Will pass within 12,649,326 km of Earth in 2057
  • Classified as a Near Earth Asteroid (NEA)
  • Classified as a Potentially Hazardous Asteroid (PHA)
  • See orbit simulation

Overview

85938 (1999 DJ4) is a small asteroid whose orbit crosses the orbit of Earth. NASA JPL has classified 1999 DJ4 as a "Potentially Hazardous Asteroid" due to its predicted close pass(es) with Earth.

1999 DJ4 orbits the sun every 921 days (2.52 years), coming as close as 0.96 AU and reaching as far as 2.75 AU from the sun. Based on its brightness and the way it reflects light, 1999 DJ4 is probably between 0.479 to 1.072 kilometers in diameter, making it larger than ~97% of asteroids but small compared to large asteroids, very roughly comparable in size to the Golden Gate Bridge.

The rotation of 1999 DJ4 has been observed. It completes a rotation on its axis every 2.51 hours.

1999 DJ4's spectral type None (Tholen) / Sq (SMASSII) indicates that it is likely to contain and .

Close Approaches

1999 DJ4's orbit is 0.03 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 DJ4 has 8 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
March 22, 2057 12,649,326 11.718
May 4, 2062 12,933,122 9.076
March 20, 2115 17,051,165 12.674
April 28, 2120 11,106,015 8.999
June 17, 2125 29,132,138 12.749
March 22, 2173 13,737,704 12.028
May 5, 2178 13,053,430 9.062
June 19, 2183 29,775,663 12.925

Images and Observations

1999 DJ4's orbit is determined by observations dating back to Feb. 24, 1999. It was last officially observed on Oct. 2, 2022. The IAU Minor Planet Center records 637 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 DJ4:

References

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Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 1.853 AU
  • Eccentricity: 0.4844
  • Inclination: 9.14°
  • Longitude of Ascending Node: 19.88°
  • Argument of Periapsis: 197.76°
  • Mean Anomaly: 245.62°

Physical Characteristics

  • Diameter: ~0.619 km
  • Magnitude: 18.72
  • Spectral type (SMASS): Sq

Derived Characteristics

  • Orbit Period: 921 days (2.52 years)
  • Avg. Orbit Speed: 21.89 km/s
  • Aphelion Distance: 2.75 AU
  • Perihelion Distance: 0.96 AU
  • Rotation Period: 2.51 hours
  • Approx. Composition: and .

Map Comparison

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Orbit Simulation

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Sky Map

The position of 85938 (1999 DJ4) 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 DJ4 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.