226554 (2003 WR21)

Very small Apollo-class Asteroid

Near-Earth Potentially Hazardous
Space Reference » Apollo-class Asteroids » 226554 (2003 WR21)

Key Facts

  • Categorized as a Apollo-class Asteroid
  • Comparable in size to the U.S. Capitol building (0.48 km diameter)
  • Will pass within 10,851,654 km of Earth in 2023
  • Classified as a Near Earth Asteroid (NEA)
  • Classified as a Potentially Hazardous Asteroid (PHA)
  • See orbit simulation

Overview

226554 (2003 WR21) is a very small asteroid whose orbit crosses the orbit of Earth. NASA JPL has classified 2003 WR21 as a "Potentially Hazardous Asteroid" due to its predicted close pass(es) with Earth.

2003 WR21 orbits the sun every 432 days (1.18 years), coming as close as 0.83 AU and reaching as far as 1.41 AU from the sun. 2003 WR21 is about 0.5 kilometers in diameter, making it larger than 90% of asteroids but tiny compared to large asteroids, comparable in size to the U.S. Capitol building.

The rotation of 2003 WR21 has been observed. It completes a rotation on its axis every 13.40 hours.

Close Approaches

2003 WR21'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.

2003 WR21 has 23 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
Jan. 9, 2023 10,851,654 8.996
June 20, 2030 9,746,611 7.631
Jan. 10, 2036 11,567,449 8.181
June 20, 2043 9,676,319 7.652
Jan. 9, 2049 10,799,868 8.721
June 9, 2056 17,173,248 6.817
Jan. 7, 2062 15,329,664 10.809
May 7, 2069 28,866,369 7.242
July 3, 2089 14,077,226 11.155
Jan. 5, 2095 22,976,168 6.275
June 28, 2102 4,775,484 8.983
Jan. 11, 2108 15,692,920 7.119
June 25, 2115 6,062,712 8.339
Jan. 10, 2121 11,751,261 8.121
June 14, 2128 15,012,477 7.006
Jan. 8, 2134 13,937,930 10.405
May 11, 2141 28,009,086 7.192
July 5, 2161 17,203,977 11.741
Jan. 3, 2167 25,518,254 6.162
June 28, 2174 5,101,617 9.108
Jan. 11, 2180 16,538,207 6.952
June 26, 2187 6,023,137 8.379
Jan. 10, 2193 12,237,590 7.942

Images and Observations

2003 WR21's orbit is determined by observations dating back to Oct. 24, 1990. It was last officially observed on June 18, 2023. The IAU Minor Planet Center records 465 observations used to determine its orbit.

Accessibility and Exploration

2003 WR21 can be reached with a journey of 370 days. This trajectory would require a delta-v of 10.544 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 1,476 potential trajectories and launch windows to this asteroid.

See more at the NHATS Mission Trajectories table for 2003 WR21.

Similar Objects

These objects have orbits that share similar characteristics to the orbit of 2003 WR21:

References

Search

   or view a random object

Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 1.118 AU
  • Eccentricity: 0.2615
  • Inclination: 9.26°
  • Longitude of Ascending Node: 85.77°
  • Argument of Periapsis: 108.09°
  • Mean Anomaly: 149.74°

Physical Characteristics

  • Diameter: 0.48200 km
  • Magnitude: 19.64
  • Albedo: 0.125

Derived Characteristics

  • Orbit Period: 432 days (1.18 years)
  • Avg. Orbit Speed: 28.15 km/s
  • Aphelion Distance: 1.41 AU
  • Perihelion Distance: 0.83 AU
  • Rotation Period: 13.40 hours

Map Comparison

Click to load map

Orbit Simulation

⧉

Sky Map

The position of 226554 (2003 WR21) 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 2003 WR21 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.