Key Facts

  • Categorized as a Aten-class Asteroid
  • Comparable in size to a football field
  • Will pass within 28,361,200 km of Earth in 2021
  • Classified as a Near Earth Asteroid (NEA)
  • Classified as a Potentially Hazardous Asteroid (PHA)
  • See orbit simulation

Overview

2021 MJ is a very small asteroid whose orbit could bring it in close proximity to Earth. NASA JPL has classified 2021 MJ as a "Potentially Hazardous Asteroid" due to its predicted close pass(es) with Earth.

2021 MJ orbits the sun every 308 days (0.84 years), coming as close as 0.72 AU and reaching as far as 1.07 AU from the sun. Based on its brightness and the way it reflects light, 2021 MJ is probably between 0.216 to 0.483 kilometers in diameter, making it a small to average asteroid, very roughly comparable in size to a football field.

Close Approaches

2021 MJ'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.

2021 MJ has 11 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
July 23, 2021 28,361,200 19.506
July 27, 2026 18,844,550 20.262
July 24, 2037 15,652,502 19.267
July 25, 2053 5,800,466 19.368
July 26, 2069 8,688,777 19.678
July 23, 2080 20,336,196 19.310
July 29, 2085 29,528,700 21.081
July 25, 2096 5,464,667 19.478
July 27, 2112 9,871,645 19.754
July 25, 2123 28,227,845 19.513
July 28, 2128 17,552,414 20.196

Images and Observations

2021 MJ's orbit is determined by observations dating back to May 24, 2021. It was last officially observed on July 29, 2021. The IAU Minor Planet Center records 37 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 MJ:

References

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Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 0.8922 AU
  • Eccentricity: 0.1955
  • Inclination: 40.11°
  • Longitude of Ascending Node: 122.84°
  • Argument of Periapsis: 20.8°
  • Mean Anomaly: 355.83°

Physical Characteristics

  • Diameter: ~0.279 km
  • Magnitude: 20.45

Derived Characteristics

  • Orbit Period: 308 days (0.84 years)
  • Avg. Orbit Speed: 31.51 km/s
  • Aphelion Distance: 1.07 AU
  • Perihelion Distance: 0.72 AU

Map Comparison

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Orbit Simulation

Sky Map

The position of 2021 MJ 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 MJ 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.