Near-Earth Object
2021 JJ
NASA ID: 54142835
2021 JJ will pass Earth on 11 May 2027 at a distance of 29.19 lunar distances (LD) - about 11,221,001 km - travelling at 24,160 km/h. Its estimated diameter is between 21 and 47 metres, roughly the size of a double-decker bus (around 11 m long). NASA does not classify it as potentially hazardous.
Close Approach Date
11 May 2027
In 324 days
Miss Distance
29.19 LD
11,221,001 km
29 times the Moon's distance from Earth
Velocity
24,160 km/h
0.9 times the orbital speed of the International Space Station
Est. Diameter
21–47 m
Absolute Magnitude
H = 25.51
The brightness measure astronomers use to estimate size
Hazard Classification
Not Hazardous
The real orbit in 3D
The actual path of 2021 JJ 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 JJ to Earth between 1927 and 2027, 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 →
