152561 (1991 RB)

Small Apollo-class Asteroid

Near-Earth Potentially Hazardous
Space Reference » Apollo-class Asteroids » 152561 (1991 RB)

Key Facts

  • Categorized as a Apollo-class Asteroid
  • Comparable in size to the Golden Gate Bridge
  • Will pass within 29,065,290 km of Earth in 2041
  • Classified as a Near Earth Asteroid (NEA)
  • Classified as a Potentially Hazardous Asteroid (PHA)
  • See orbit simulation

Overview

152561 (1991 RB) is a small asteroid whose orbit crosses the orbit of Earth. NASA JPL has classified 1991 RB as a "Potentially Hazardous Asteroid" due to its predicted close pass(es) with Earth.

1991 RB orbits the sun every 641 days (1.75 years), coming as close as 0.75 AU and reaching as far as 2.16 AU from the sun. Based on its brightness and the way it reflects light, 1991 RB is probably between 0.402 to 0.900 kilometers in diameter, making it larger than ~97% of asteroids but small compared to large asteroids, very roughly comparable in size to the Golden Gate Bridge.

Close Approaches

1991 RB'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.

1991 RB has 12 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
Feb. 21, 2041 29,065,290 14.024
Feb. 25, 2048 25,198,254 16.255
Feb. 28, 2055 29,604,650 18.825
Sept. 9, 2084 20,564,542 19.765
Sept. 15, 2091 8,532,389 17.646
Sept. 18, 2098 5,629,740 16.347
Sept. 24, 2105 13,232,610 14.928
Oct. 2, 2112 25,043,053 13.513
Feb. 23, 2155 29,193,769 13.822
Feb. 25, 2162 24,376,498 15.994
Feb. 28, 2169 27,734,563 18.450
Sept. 10, 2198 20,835,724 19.849

Images and Observations

1991 RB's orbit is determined by observations dating back to Aug. 19, 1977. It was last officially observed on April 27, 2020. The IAU Minor Planet Center records 117 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 1991 RB:

References

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Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 1.454 AU
  • Eccentricity: 0.4857
  • Inclination: 19.58°
  • Longitude of Ascending Node: 359.3°
  • Argument of Periapsis: 68.94°
  • Mean Anomaly: 55.07°

Physical Characteristics

  • Diameter: ~0.519 km
  • Magnitude: 19.1

Derived Characteristics

  • Orbit Period: 641 days (1.75 years)
  • Avg. Orbit Speed: 24.68 km/s
  • Aphelion Distance: 2.16 AU
  • Perihelion Distance: 0.75 AU

Map Comparison

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Orbit Simulation

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Sky Map

The position of 152561 (1991 RB) 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 1991 RB 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.