Key Facts

  • Categorized as a Apollo-class Asteroid
  • Comparable in size to the U.S. Capitol building
  • Will pass within 19,909,011 km of Earth in 2020
  • Classified as a Near Earth Asteroid (NEA)
  • Not a Potentially Hazardous Object
  • See orbit simulation


2015 OX78 is a very small asteroid whose orbit crosses the orbit of Earth. NASA JPL has classified 2015 OX78 as a "Near Earth Asteroid" due to its orbit's proximity to Earth, but it is not considered potentially hazardous because computer simulations have not indicated any imminent likelihood of future collision.

2015 OX78 orbits the sun every 722 days (1.98 years), coming as close as 0.95 AU and reaching as far as 2.20 AU from the sun. Based on its brightness and the way it reflects light, 2015 OX78 is probably between 0.266 to 0.594 kilometers in diameter, making it small in absolute terms, but larger than 90% of asteroids, very roughly comparable in size to the U.S. Capitol building.

Close Approaches

2015 OX78's orbit is 0.13 AU from Earth's orbit at its closest point. This means that there is an wide berth between this asteroid and Earth at all times.

2015 OX78 has 6 close approaches predicted in the coming decades:

Date Distance from Earth (km) Velocity (km/s)
Jan. 16, 2020 19,909,011 22.841
Jan. 13, 2022 29,438,991 21.542
Jan. 20, 2101 27,404,033 24.423
Jan. 17, 2103 20,282,587 22.669
Jan. 20, 2184 25,885,849 24.180
Jan. 16, 2186 20,974,529 22.491

Images and Observations

2015 OX78's orbit is determined by observations dating back to June 28, 2015. It was last officially observed on Feb. 17, 2020. The IAU Minor Planet Center records 297 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 2015 OX78:



   or view a random object

Orbital Elements

  • Epoch: 2459000.5 JD
  • Semi-major axis: 1.575 AU
  • Eccentricity: 0.395
  • Inclination: 40.42°
  • Longitude of Ascending Node: 119.51°
  • Argument of Periapsis: 296.29°
  • Mean Anomaly: 93.46°

Physical Characteristics

  • Diameter: ~0.343 km
  • Magnitude: 20.0

Derived Characteristics

  • Orbit Period: 722 days (1.98 years)
  • Avg. Orbit Speed: 23.73 km/s
  • Aphelion Distance: 2.20 AU
  • Perihelion Distance: 0.95 AU

Size Comparison

Orbit Simulation

Sky Map

The position of 2015 OX78 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.