Key Facts

  • Categorized as a Apollo-class Asteroid
  • Comparable in size to a school bus or smaller
  • Will pass within 23,768,347 km of Earth in 2020
  • Classified as a Near Earth Asteroid (NEA)
  • Not a Potentially Hazardous Object
  • See orbit simulation

Overview

2021 JA4 is a very small asteroid whose orbit crosses the orbit of Earth. NASA JPL has classified 2021 JA4 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.

2021 JA4 orbits the sun every 551 days (1.51 years), coming as close as 0.94 AU and reaching as far as 1.69 AU from the sun. Based on its brightness and the way it reflects light, 2021 JA4 is probably between 0.093 to 0.207 kilometers in diameter, making it a small to average asteroid, very roughly comparable in size to a school bus or smaller.

Close Approaches

2021 JA4's orbit is 0.05 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.

2021 JA4 has 12 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
Oct. 27, 2020 23,768,347 16.980
Oct. 31, 2023 10,593,026 15.408
Nov. 3, 2026 8,648,629 14.327
Nov. 6, 2029 20,756,092 13.586
Oct. 27, 2103 29,446,023 17.723
Oct. 31, 2106 14,999,176 15.930
Nov. 3, 2109 7,073,539 14.625
Nov. 6, 2112 16,616,051 13.748
Oct. 27, 2186 29,530,762 17.734
Oct. 31, 2189 14,904,359 15.927
Nov. 3, 2192 7,208,312 14.605
Nov. 7, 2195 17,066,725 13.712

Images and Observations

2021 JA4's orbit is determined by observations dating back to April 25, 2015. It was last officially observed on May 11, 2021. The IAU Minor Planet Center records 24 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 2021 JA4:

References

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Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 1.315 AU
  • Eccentricity: 0.2856
  • Inclination: 25.14°
  • Longitude of Ascending Node: 217.56°
  • Argument of Periapsis: 236.61°
  • Mean Anomaly: 298.0°

Physical Characteristics

  • Diameter: ~0.120 km
  • Magnitude: 22.29

Derived Characteristics

  • Orbit Period: 551 days (1.51 years)
  • Avg. Orbit Speed: 25.96 km/s
  • Aphelion Distance: 1.69 AU
  • Perihelion Distance: 0.94 AU

Map Comparison

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Orbit Simulation

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Sky Map

The position of 2021 JA4 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 2021 JA4 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.