Key Facts
- Categorized as a Apollo-class Asteroid
- Comparable in size to a school bus or smaller
- Will pass within 1,662,761 km of Earth in 2021
- Classified as a Near Earth Asteroid (NEA)
- Not a Potentially Hazardous Object
- See orbit simulation
Overview
2021 PJ1 is a very small asteroid whose orbit crosses the orbit of Earth. NASA JPL has classified 2021 PJ1 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 PJ1 orbits the sun every 487 days (1.33 years), coming as close as 0.80 AU and reaching as far as 1.63 AU from the sun. Based on its brightness and the way it reflects light, 2021 PJ1 is probably between 0.012 to 0.053 kilometers in diameter, making it a small to average asteroid, very roughly comparable in size to a school bus or smaller.
Close Approaches
2021 PJ1's orbit is 0.01 AU from Earth's orbit at its closest point. This means that its orbit is relatively close to Earth's orbit.
2021 PJ1 has 9 close approaches predicted in the coming decades:
| Date | Distance from Earth (km) | Velocity (km/s) |
|---|---|---|
| Aug. 15, 2021 | 1,662,761 | 9.243 |
| Aug. 15, 2025 | 1,674,767 | 9.264 |
| Aug. 31, 2029 | 16,598,010 | 6.653 |
| Oct. 5, 2033 | 26,514,510 | 7.907 |
| Oct. 31, 2037 | 29,141,020 | 8.649 |
| Nov. 26, 2041 | 26,543,143 | 8.020 |
| Dec. 30, 2045 | 16,861,366 | 6.630 |
| Jan. 16, 2050 | 2,119,785 | 9.117 |
| Jan. 16, 2054 | 1,627,020 | 9.264 |
Images and Observations
2021 PJ1's orbit is determined by observations dating back to Aug. 4, 2021. It was last officially observed on Aug. 14, 2021. The IAU Minor Planet Center records 80 observations used to determine its orbit.
Accessibility and Exploration
2021 PJ1 can be reached with a journey of 450 days. This trajectory would require a delta-v of 9.828 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 21,062 potential trajectories and launch windows to this asteroid.
See more at the NHATS Mission Trajectories table for 2021 PJ1.
Similar Objects
These objects have orbits that share similar characteristics to the orbit of 2021 PJ1:References
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or view a random objectOrbital Elements
- Epoch: 2460200.5 JD
- Semi-major axis: 1.211 AU
- Eccentricity: 0.343
- Inclination: 0.37°
- Longitude of Ascending Node: 232.69°
- Argument of Periapsis: 169.59°
- Mean Anomaly: 156.84°
Physical Characteristics
- Diameter: ~0.033 km
- Magnitude: 25.84
Derived Characteristics
- Orbit Period: 487 days (1.33 years)
- Avg. Orbit Speed: 27.05 km/s
- Aphelion Distance: 1.63 AU
- Perihelion Distance: 0.80 AU
Map Comparison
Orbit Simulation
Sky Map
The position of 2021 PJ1 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 PJ1 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.
