403775 (2011 HS4)

Very small Aten-class Asteroid

Near-Earth Potentially Hazardous
Space Reference » Aten-class Asteroids » 403775 (2011 HS4)

Key Facts

  • Categorized as a Aten-class Asteroid
  • Comparable in size to a football field
  • Will pass within 27,067,736 km of Earth in 2020
  • Classified as a Near Earth Asteroid (NEA)
  • Classified as a Potentially Hazardous Asteroid (PHA)
  • See orbit simulation

Overview

403775 (2011 HS4) is a very small asteroid whose orbit could bring it in close proximity to Earth. NASA JPL has classified 2011 HS4 as a "Potentially Hazardous Asteroid" due to its predicted close pass(es) with Earth.

2011 HS4 orbits the sun every 332 days (0.91 years), coming as close as 0.30 AU and reaching as far as 1.58 AU from the sun. Based on its brightness and the way it reflects light, 2011 HS4 is probably between 0.176 to 0.393 kilometers in diameter, making it a small to average asteroid, very roughly comparable in size to a football field.

Close Approaches

2011 HS4'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.

2011 HS4 has 17 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
April 23, 2020 27,067,736 25.579
April 23, 2030 25,938,040 25.282
April 23, 2040 26,742,238 25.490
April 24, 2050 27,360,383 25.653
April 24, 2060 29,686,208 26.202
July 11, 2105 29,604,415 27.056
July 11, 2115 28,259,823 26.773
July 12, 2125 24,973,587 26.070
July 13, 2135 23,610,317 25.790
July 13, 2145 20,080,903 25.069
July 14, 2155 19,736,589 24.984
July 14, 2165 16,542,444 24.324
April 18, 2171 29,223,185 16.344
July 15, 2175 15,280,902 24.080
April 18, 2181 29,888,545 16.255
July 14, 2185 18,097,646 24.654
July 13, 2195 23,278,822 25.717

Images and Observations

2011 HS4's orbit is determined by observations dating back to June 1, 2002. It was last officially observed on July 6, 2023. The IAU Minor Planet Center records 126 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 2011 HS4:

References

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Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 0.9383 AU
  • Eccentricity: 0.6801
  • Inclination: 5.46°
  • Longitude of Ascending Node: 117.49°
  • Argument of Periapsis: 314.28°
  • Mean Anomaly: 313.65°

Physical Characteristics

  • Diameter: ~0.227 km
  • Magnitude: 20.9

Derived Characteristics

  • Orbit Period: 332 days (0.91 years)
  • Avg. Orbit Speed: 30.75 km/s
  • Aphelion Distance: 1.58 AU
  • Perihelion Distance: 0.30 AU

Map Comparison

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Orbit Simulation

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Sky Map

The position of 403775 (2011 HS4) 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 2011 HS4 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.