Near-Earth Object
2021 HD
NASA ID: 54138304
2021 HD will pass Earth on 26 November 2026 at a distance of 87.89 lunar distances (LD) - about 33,785,026 km - travelling at 38,404 km/h. Its estimated diameter is between 15 and 33 metres, roughly the size of a double-decker bus (around 11 m long). NASA does not classify it as potentially hazardous.
Close Approach Date
26 November 2026
In 159 days
Miss Distance
87.89 LD
33,785,026 km
88 times the Moon's distance from Earth
Velocity
38,404 km/h
1.4 times the orbital speed of the International Space Station
Est. Diameter
15–33 m
Absolute Magnitude
H = 26.27
The brightness measure astronomers use to estimate size
Hazard Classification
Not Hazardous
The real orbit in 3D
The actual path of 2021 HD around the Sun, computed from JPL orbital elements. Drag to rotate, scroll to zoom, and use the time controls to run the orbit forwards or back.
Every recorded pass
Each dot is one close approach of 2021 HD to Earth between 1906 and 2062, from JPL's records. Lower means closer: a dot under the dashed line passed nearer than the Moon. The orange dot is the approach on this page.
Size Comparison
Reading the Numbers
- A lunar distance (LD) is the average gap between Earth and the Moon, about 384,400 km. It is the standard yardstick for close approaches. Read more →
- Diameter estimates come from brightness. A dark surface reflects less light than a bright one, so the true size can sit anywhere in the quoted range. Read more →
- Potentially hazardous is a watch-list label based on size and orbital proximity. It does not mean an impact is expected. Read more →
