Key Facts

  • Classified as a Apollo-class Asteroid
  • Comparable in size to the Golden Gate Bridge (0.49 km diameter)
  • Will pass within 14,767,515 km of Earth in 2037
  • Classified as a Near Earth Asteroid (NEA)
  • Classified as a Potentially Hazardous Asteroid (PHA)
  • See orbit simulation

Overview

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

Bennu orbits the sun every 437 days (1.20 years), coming as close as 0.90 AU and reaching as far as 1.36 AU from the sun. Bennu is about 0.5 kilometers in diameter, making it a small to average asteroid, comparable in size to the Golden Gate Bridge.

The rotation of Bennu has been observed. It completes a rotation on its axis every 4.30 days.

Bennu's spectral type (Tholen) / B (SMASSII) indicates that it is likely to contain iron, hydrogen, ammonia, and nitrogen.

Close Approaches

Bennu's orbit is 0.00 AU from Earth's orbit at its closest point. This means that its orbit is relatively close to Earth's orbit.

Bennu has 15 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
Feb. 11, 2037 14,767,515 7.534
Feb. 9, 2043 14,455,363 4.301
Nov. 14, 2048 18,018,942 4.661
March 7, 2049 27,371,236 4.474
Sept. 30, 2054 5,879,142 5.092
Sept. 23, 2060 749,193 6.187
Feb. 15, 2068 10,542,653 5.746
Sept. 22, 2080 2,328,001 6.390
Oct. 2, 2087 7,944,826 4.809
Nov. 26, 2094 19,866,300 4.612
March 13, 2095 25,989,003 4.495
Feb. 17, 2102 11,989,002 4.837
Feb. 19, 2109 16,836,627 8.279
Sept. 14, 2128 20,013,775 9.553
Sept. 25, 2135 297,889 6.169

NASA Sentry has assessed impact risk for 78 very close approach scenarios. Here are the top scenarios ordered by probability of impact:

Date Distance from Earth (km) Distance Error (km) Probability of Impact (%) Impact Energy (Mt)
Sept. 24, 2196 969.42 ±0.00 0.00940 1151.0
Sept. 24, 2185 243.96 ±0.00 0.00630 1152.0
Sept. 25, 2175 1,502.28 ±0.00 0.00410 1151.0
Sept. 24, 2196 6.42 ±0.00 0.00350 1151.0
Sept. 24, 2193 38.52 ±0.00 0.00280 1152.0
Sept. 24, 2185 468.66 ±0.00 0.00200 1151.0
Sept. 24, 2180 738.30 ±0.00 0.00200 1150.0
Sept. 24, 2180 1,226.22 ±0.00 0.00110 1152.0
Sept. 25, 2187 5,540.46 ±0.00 0.00083 1152.0
Sept. 25, 2175 2,908.26 ±0.00 0.00064 1151.0
Sept. 25, 2191 173.34 ±0.00 0.00054 1150.0
Sept. 24, 2182 1,804.02 ±0.00 0.00035 1151.0
Sept. 24, 2176 1,117.08 ±0.00 0.00031 1152.0
Sept. 24, 2181 44.94 ±0.00 0.00029 1151.0
Sept. 24, 2194 3,652.98 ±0.00 0.00018 1151.0
Sept. 24, 2198 2,580.84 ±0.00 0.00015 1152.0
Sept. 24, 2186 3,486.06 ±0.00 0.00015 1151.0
Sept. 25, 2191 4,243.62 ±0.00 0.00014 1150.0
Sept. 24, 2181 1,110.66 ±0.00 0.00014 1151.0
Sept. 24, 2182 475.08 ±0.00 0.00014 1151.0
Sept. 25, 2191 1,065.72 ±0.00 0.00013 1150.0
Sept. 24, 2190 89.88 ±0.00 0.00012 1152.0
Sept. 25, 2191 205.44 ±0.00 0.00010 1150.0
Sept. 24, 2186 19.26 ±0.00 0.00009 1150.0
Sept. 24, 2199 5,007.60 ±0.00 0.00009 1152.0
Sept. 24, 2194 1,155.60 ±0.00 0.00009 1151.0
Sept. 24, 2193 115.56 ±0.00 0.00009 1151.0
Sept. 24, 2192 532.86 ±0.00 0.00008 1154.0
Sept. 25, 2186 1,893.90 ±0.00 0.00008 1151.0
Sept. 24, 2188 5,752.32 ±0.00 0.00008 1150.0
Sept. 24, 2198 442.98 ±0.00 0.00008 1150.0
Sept. 24, 2194 51.36 ±0.00 0.00007 1153.0
Sept. 24, 2190 1,271.16 ±0.00 0.00007 1152.0
Sept. 24, 2181 1,431.66 ±0.00 0.00006 1152.0
Sept. 24, 2192 1,104.24 ±0.00 0.00006 1151.0
Sept. 25, 2191 4,673.76 ±0.00 0.00006 1150.0
Sept. 25, 2187 12.84 ±0.00 0.00005 1152.0
Sept. 25, 2195 1,887.48 ±0.00 0.00004 1152.0
Sept. 25, 2199 1,540.80 ±0.00 0.00004 1150.0
Sept. 25, 2190 1,739.82 ±0.00 0.00004 1152.0
Sept. 24, 2192 64.20 ±0.00 0.00003 1152.0
Sept. 24, 2198 19.26 ±0.00 0.00003 1151.0
Sept. 24, 2199 545.70 ±0.00 0.00003 1150.0
Sept. 25, 2187 2,895.42 ±0.00 0.00002 1152.0
Sept. 24, 2194 2,221.32 ±0.00 0.00002 1151.0
Sept. 24, 2198 5,668.86 ±0.00 0.00001 1152.0
Sept. 24, 2187 179.76 ±0.00 0.00001 1152.0
Sept. 24, 2181 44.94 ±0.00 0.00001 1152.0
Sept. 24, 2196 4,089.54 ±0.00 0.00001 1152.0
Sept. 24, 2193 4,217.94 ±0.00 0.00001 1151.0
Sept. 24, 2187 847.44 ±0.00 0.00000 1152.0
Sept. 24, 2190 513.60 ±0.00 0.00000 1151.0
Sept. 24, 2196 333.84 ±0.00 0.00000 1152.0
Sept. 24, 2197 51.36 ±0.00 0.00000 1151.0
Sept. 25, 2193 796.08 ±0.00 0.00000 1151.0
Sept. 24, 2188 6,323.70 ±0.00 0.00000 1150.0
Sept. 24, 2185 1,450.92 ±0.00 0.00000 1151.0
Sept. 24, 2193 609.90 ±0.00 0.00000 1151.0
Sept. 24, 2182 1,251.90 ±0.00 0.00000 1151.0
Sept. 24, 2181 3,646.56 ±0.00 0.00000 1152.0
Sept. 24, 2184 121.98 ±0.00 0.00000 1152.0
Sept. 24, 2185 2,317.62 ±0.00 0.00000 1151.0
Sept. 24, 2190 4,718.70 ±0.00 0.00000 1152.0
Sept. 24, 2198 6.42 ±0.00 0.00000 1153.0
Sept. 24, 2185 526.44 ±0.00 0.00000 1151.0
Sept. 24, 2193 121.98 ±0.00 0.00000 1151.0
Sept. 24, 2193 32.10 ±0.00 0.00000 1151.0
Sept. 24, 2198 121.98 ±0.00 0.00000 1152.0
Sept. 25, 2199 1,675.62 ±0.00 0.00000 1150.0
Sept. 24, 2197 5,855.04 ±0.00 0.00000 1151.0
Sept. 24, 2198 1,630.68 ±0.00 0.00000 1152.0
Sept. 23, 2196 982.26 ±0.00 0.00000 1151.0
Sept. 25, 2189 1,893.90 ±0.00 0.00000 1152.0
Sept. 24, 2187 1,669.20 ±0.00 0.00000 1152.0
Sept. 24, 2198 5,219.46 ±0.00 0.00000 1151.0
Sept. 24, 2184 2,754.18 ±0.00 0.00000 1152.0
Sept. 25, 2187 731.88 ±0.00 0.00000 1153.0
Sept. 24, 2192 1,328.94 ±0.00 0.00000 1152.0

Images and Observations

Bennu's orbit is determined by observations dating back to Sept. 11, 1999. It was last officially observed on May 15, 2018. The IAU Minor Planet Center records 518 observations used to determine its orbit.

Accessibility and Exploration

Bennu can be reached with a journey of 362 days. This trajectory would require a delta-v of 6.965 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 25,975 potential trajectories and launch windows to this asteroid.

See more at the NHATS Mission Trajectories table for Bennu.

Similar Objects

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

References

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Orbital Elements

  • Epoch: 2455562.5 JD
  • Semi-major axis: 1.12639102593 AU
  • Eccentricity: 0.203745108479
  • Inclination: 6.03493953361°
  • Longitude of Ascending Node: 2.06086732937°
  • Argument of Periapsis: 66.2230684609°
  • Mean Anomaly: 101.703947947°

Physical Characteristics

  • Diameter: 0.49200 km
  • Magnitude: 20.19
  • Albedo: 0.046
  • Spectral type (SMASS): B

Derived Characteristics

  • Orbit Period: 437 days (1.20 years)
  • Avg. Orbit Speed: 28.06 km/s
  • Aphelion Distance: 1.36 AU
  • Perihelion Distance: 0.90 AU
  • Rotation Period: 4.30 days
  • Approx. Composition: iron, hydrogen, ammonia, and nitrogen.

Size Comparison

Orbit Simulation

Sky Map

The position of Bennu 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.