Key Facts

Overview

Twilley is a mid-sized asteroid orbiting between Mars and Jupiter in the main portion of the asteroid belt. NASA JPL has not classified Twilley as potentially hazardous because its orbit does not bring it close to Earth.

Twilley orbits the sun every 1,260 days (3.45 years), coming as close as 2.08 AU and reaching as far as 2.48 AU from the sun. Twilley is about 4.5 kilometers in diameter, making it larger than 99% of asteroids, comparable in size to the island of Manhattan.

The rotation of Twilley has been observed. It completes a rotation on its axis every 2.96 hours.

No Close Approaches

Twilley's orbit is 1.09 AU from Earth's orbit at its closest point. This means that there is an extremely wide berth between this asteroid and Earth at all times.

Orbital simulations conducted by NASA JPL's CNEOS do not show any close approaches to Earth.

Images and Observations

Twilley's orbit is determined by observations dating back to March 23, 1955. It was last officially observed on Feb. 19, 2023. The IAU Minor Planet Center records 3,150 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 Twilley:

References

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Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 2.28 AU
  • Eccentricity: 0.0883
  • Inclination: 4.4°
  • Longitude of Ascending Node: 112.46°
  • Argument of Periapsis: 340.83°
  • Mean Anomaly: 17.9°

Physical Characteristics

  • Diameter: 4.48300 km
  • Magnitude: 13.78
  • Albedo: 0.350

Derived Characteristics

  • Orbit Period: 1,260 days (3.45 years)
  • Avg. Orbit Speed: 19.69 km/s
  • Aphelion Distance: 2.48 AU
  • Perihelion Distance: 2.08 AU
  • Rotation Period: 2.96 hours

Map Comparison

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Orbit Simulation

Sky Map

The position of Twilley 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 above comparison is an artistic rendering that uses available data on the diameter of Twilley to create an approximate landscape rendering with Mount Everest in the background. This approximation is built for full-resolution desktop browsers. Shape, color, and texture of asteroid are imagined.