2021 WA1

Very small Aten-class Asteroid

Near-Earth
Space Reference » Aten-class Asteroids » 2021 WA1

Key Facts

  • Categorized as a Aten-class Asteroid
  • Comparable in size to a school bus or smaller
  • Will pass within 12,643,141 km of Earth in 2019
  • Classified as a Near Earth Asteroid (NEA)
  • Not a Potentially Hazardous Object
  • See orbit simulation

Overview

2021 WA1 is a very small asteroid whose orbit could bring it in close proximity to Earth. NASA JPL has classified 2021 WA1 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 WA1 orbits the sun every 362 days (0.99 years), coming as close as 0.56 AU and reaching as far as 1.43 AU from the sun. Based on its brightness and the way it reflects light, 2021 WA1 is probably between 0.008 to 0.017 kilometers in diameter, making it a small to average asteroid, very roughly comparable in size to a school bus or smaller.

Close Approaches

2021 WA1's orbit is 0.00 AU from Earth's orbit at its closest point. This means that its orbit is very close to Earth's orbit.

2021 WA1 has 12 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
Nov. 25, 2019 12,643,141 11.386
Nov. 25, 2020 6,080,233 12.671
Nov. 26, 2021 308,347 13.899
Nov. 25, 2022 9,089,368 12.082
Nov. 25, 2023 18,339,823 10.366
Nov. 28, 2024 27,555,419 9.134
April 4, 2046 24,562,959 9.467
April 5, 2047 16,222,580 10.962
April 3, 2048 9,045,700 12.661
April 2, 2049 7,126,491 14.336
March 31, 2050 12,951,217 16.081
March 29, 2051 21,205,867 17.941

NASA Sentry has assessed impact risk for 2 very close approach scenarios. Here are the top scenarios ordered by probability of impact:

Date Probability of Impact (%) Impact Energy (Mt)
Nov. 27, 2116 0.03090 0.05776
Nov. 28, 2117 0.00442 0.05786

Images and Observations

2021 WA1's orbit is determined by observations dating back to Nov. 27, 2021. It was last officially observed on Dec. 4, 2021. The IAU Minor Planet Center records 74 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 WA1:

References

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Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 0.9933 AU
  • Eccentricity: 0.4358
  • Inclination: 3.26°
  • Longitude of Ascending Node: 65.23°
  • Argument of Periapsis: 243.93°
  • Mean Anomaly: 356.66°

Physical Characteristics

  • Diameter: ~0.010 km
  • Magnitude: 27.7

Derived Characteristics

  • Orbit Period: 362 days (0.99 years)
  • Avg. Orbit Speed: 29.85 km/s
  • Aphelion Distance: 1.43 AU
  • Perihelion Distance: 0.56 AU

Map Comparison

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Orbit Simulation

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Sky Map

The position of 2021 WA1 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.