Key Facts


101901 (1999 QD2) is a mid-sized asteroid with an orbit that crosses the orbit of Mars. NASA JPL has not classified 1999 QD2 as potentially hazardous because its orbit does not bring it close to Earth.

1999 QD2 orbits the sun every 800 days (2.19 years), coming as close as 1.58 AU and reaching as far as 1.79 AU from the sun. Based on its brightness and the way it reflects light, 1999 QD2 is probably between 0.939 to 2.099 kilometers in diameter, making it larger than 99% of asteroids, very roughly comparable in size to the U.S. Pentagon.

No Close Approaches

1999 QD2's orbit is 0.61 AU from Earth's orbit at its closest point. This means that there is an very 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 QD2's orbit is determined by observations dating back to July 22, 1999. It was last officially observed on Aug. 8, 2021. The IAU Minor Planet Center records 534 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 QD2:



   or view a random object

Orbital Elements

  • Epoch: 2459396.5 JD
  • Semi-major axis: 1.686 AU
  • Eccentricity: 0.0609
  • Inclination: 23.29°
  • Longitude of Ascending Node: 154.02°
  • Argument of Periapsis: 122.98°
  • Mean Anomaly: 44.43°

Physical Characteristics

  • Diameter: ~1.212 km
  • Magnitude: 17.26

Derived Characteristics

  • Orbit Period: 800 days (2.19 years)
  • Avg. Orbit Speed: 22.93 km/s
  • Aphelion Distance: 1.79 AU
  • Perihelion Distance: 1.58 AU

Map Comparison

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Orbit Simulation

Sky Map

The position of 101901 (1999 QD2) 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 1999 QD2 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.