Key Facts

  • Categorized as a Aten-class Asteroid
  • Comparable in size to a school bus or smaller
  • Will pass within 3,417,331 km of Earth in 2021
  • Classified as a Near Earth Asteroid (NEA)
  • Not a Potentially Hazardous Object
  • See orbit simulation

Overview

2021 JJ4 is a very small asteroid whose orbit could bring it in close proximity to Earth. NASA JPL has classified 2021 JJ4 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 JJ4 orbits the sun every 288 days (0.79 years), coming as close as 0.56 AU and reaching as far as 1.15 AU from the sun. Based on its brightness and the way it reflects light, 2021 JJ4 is probably between 0.010 to 0.046 kilometers in diameter, making it a small to average asteroid, very roughly comparable in size to a school bus or smaller.

Close Approaches

2021 JJ4's orbit is 0.02 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 JJ4 has 9 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
April 24, 2021 3,417,331 8.644
June 19, 2025 20,323,467 7.067
July 18, 2029 22,616,988 12.717
April 26, 2047 28,898,353 14.731
April 23, 2062 13,198,018 11.419
July 20, 2070 12,785,886 9.931
April 23, 2077 3,644,772 9.261
July 19, 2085 17,019,923 11.276
April 23, 2092 3,240,082 9.093

Images and Observations

2021 JJ4's orbit is determined by observations dating back to May 8, 2021. It was last officially observed on May 11, 2021. The IAU Minor Planet Center records 9 observations used to determine its orbit.

Accessibility and Exploration

2021 JJ4 can be reached with a journey of 354 days. This trajectory would require a delta-v of 10.44 km/s. To put this into perspective, the delta-v to launch a rocket to Low-Earth Orbit is 9.7 km/s. There are 4,372 potential trajectories and launch windows to this asteroid.

See more at the NHATS Mission Trajectories table for 2021 JJ4.

Similar Objects

These objects have orbits that share similar characteristics to the orbit of 2021 JJ4:

References

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Orbital Elements

  • Epoch: 2459343.5 JD
  • Semi-major axis: 0.8538 AU
  • Eccentricity: 0.3477
  • Inclination: 4.49°
  • Longitude of Ascending Node: 228.87°
  • Argument of Periapsis: 206.91°
  • Mean Anomaly: 124.61°

Physical Characteristics

  • Diameter: ~0.028 km
  • Magnitude: 26.13

Derived Characteristics

  • Orbit Period: 288 days (0.79 years)
  • Avg. Orbit Speed: 32.25 km/s
  • Aphelion Distance: 1.15 AU
  • Perihelion Distance: 0.56 AU

Map Comparison

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Orbit Simulation

Sky Map

The position of 2021 JJ4 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 JJ4 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.