Near-Earth Object
308242 (2005 GO21
NASA ID: 20308242
308242 (2005 GO21 will pass Earth on 20 June 2027 at a distance of 76.36 lunar distances (LD) - about 29,352,076 km - travelling at 45,940 km/h. Its estimated diameter is between 1,544 and 3,452 metres, roughly the size of Mount Everest (8,849 m tall). NASA classifies it as a potentially hazardous asteroid (PHA) - a designation based on size and orbital proximity, not on any predicted impact.
Close Approach Date
20 June 2027
In 352 days
Miss Distance
76.36 LD
29,352,076 km
76 times the Moon's distance from Earth
Velocity
45,940 km/h
1.7 times the orbital speed of the International Space Station
Est. Diameter
1,544–3,452 m
Absolute Magnitude
H = 16.18
The brightness measure astronomers use to estimate size
Hazard Classification
Potentially Hazardous
A watch-list label based on size and orbit, not a predicted impact
The real orbit in 3D
The actual path of 308242 (2005 GO21 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 308242 (2005 GO21 to Earth between 1912 and 2095, 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 →
