Key Facts

Overview

17129 (1999 JM78) is a mid-sized asteroid orbiting between Mars and Jupiter in the main portion of the asteroid belt. NASA JPL has not classified 1999 JM78 as potentially hazardous because its orbit does not bring it close to Earth.

1999 JM78 orbits the sun every 1,550 days (4.24 years), coming as close as 2.51 AU and reaching as far as 2.73 AU from the sun. Based on its brightness and the way it reflects light, 1999 JM78 is probably between 7.220 to 16.145 kilometers in diameter, making it larger than 99% of asteroids, very roughly comparable in size to the San Francisco Bay.

The rotation of 1999 JM78 has been observed. It completes a rotation on its axis every 6.26 hours.

No Close Approaches

1999 JM78's orbit is 1.52 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

1999 JM78's orbit is determined by observations dating back to July 28, 1949. It was last officially observed on March 31, 2023. The IAU Minor Planet Center records 4,673 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 1999 JM78:

References

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Orbital Elements

  • Epoch: 2460200.5 JD
  • Semi-major axis: 2.617 AU
  • Eccentricity: 0.0418
  • Inclination: 15.19°
  • Longitude of Ascending Node: 134.61°
  • Argument of Periapsis: 113.54°
  • Mean Anomaly: 236.83°

Physical Characteristics

  • Diameter: ~9.321 km
  • Magnitude: 12.83

Derived Characteristics

  • Orbit Period: 1,550 days (4.24 years)
  • Avg. Orbit Speed: 18.37 km/s
  • Aphelion Distance: 2.73 AU
  • Perihelion Distance: 2.51 AU
  • Rotation Period: 6.26 hours

Map Comparison

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Orbit Simulation

Sky Map

The position of 17129 (1999 JM78) 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.