Key Facts

  • Categorized as a Amor-class Asteroid
  • Comparable in size to a school bus or smaller
  • Will pass within 7,697,962 km of Earth in 2021
  • Classified as a Near Earth Asteroid (NEA)
  • Not a Potentially Hazardous Object
  • See orbit simulation


2021 JJ is a very small asteroid whose orbit approaches the orbit of Earth but does not cross it. NASA JPL has classified 2021 JJ 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 JJ orbits the sun every 547 days (1.50 years), coming as close as 1.03 AU and reaching as far as 1.58 AU from the sun. Based on its brightness and the way it reflects light, 2021 JJ is probably between 0.014 to 0.061 kilometers in diameter, making it a small to average asteroid, very roughly comparable in size to a school bus or smaller.

Close Approaches

2021 JJ's orbit is 0.04 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 JJ has 8 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
May 19, 2021 7,697,962 5.262
May 15, 2024 6,570,212 5.797
May 10, 2027 12,919,085 6.989
May 4, 2030 25,406,833 9.084
May 20, 2109 7,731,583 5.274
May 16, 2112 6,891,495 5.864
May 11, 2115 13,732,967 7.157
May 5, 2118 26,403,909 9.295

Images and Observations

2021 JJ's orbit is determined by observations dating back to April 18, 2021. It was last officially observed on May 20, 2021. The IAU Minor Planet Center records 47 observations used to determine its orbit.

Accessibility and Exploration

2021 JJ can be reached with a journey of 370 days. This trajectory would require a delta-v of 9.573 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 4,651 potential trajectories and launch windows to this asteroid.

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

Similar Objects

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



   or view a random object

Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 1.308 AU
  • Eccentricity: 0.209
  • Inclination: 8.45°
  • Longitude of Ascending Node: 47.95°
  • Argument of Periapsis: 209.89°
  • Mean Anomaly: 183.93°

Physical Characteristics

  • Diameter: ~0.038 km
  • Magnitude: 25.53

Derived Characteristics

  • Orbit Period: 547 days (1.50 years)
  • Avg. Orbit Speed: 26.01 km/s
  • Aphelion Distance: 1.58 AU
  • Perihelion Distance: 1.03 AU

Map Comparison

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Orbit Simulation

Sky Map

The position of 2021 JJ 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 JJ 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.