Answer & explanation
The official answer, with Fermi’s reasoning step by step.
Answer & explanation
Official answer
84
feet
How to estimate it
Fermi’s official “Napkin math”
Earth sits about 93 million miles from the Sun. How wide is the Sun? About 100 Earths at 8,000 miles each, so 800,000 miles, and a basketball is about 9 inches across.
- Earth to Sun
- 93,000,000 mi
- Sun's width
- ÷ 800,000 mi
- Basketballs apart
- ≈ 115
- 115 × 9 in
- ≈ 1,035 in ≈ 86 ft
Earth sits about 150 million kilometers from the Sun. How wide is the Sun? About 100 Earths at 13,000 km each, so 1.3 million km, and a basketball is about 25 cm across.
- Earth to Sun
- 150,000,000 km
- Sun's width
- ÷ 1,300,000 km
- Basketballs apart
- ≈ 115
- 115 × 25 cm
- ≈ 29 m
Rounded assumptions may give a slightly different estimate. The official answer above is the game’s reference value.
Source calculation & reference
- Earth to Sun, 1 astronomical unit (IAU)
- 149,597,871 km
- Sun's diameter (NASA, 2 × 695,700 km)
- ÷ 1,391,400 km ≈ 107.5
- NBA ball, 29.5 in around
- × 9.39 in across
- 107.5 × 9.39 in
- ≈ 1,010 in ≈ 84 ft
Reference cited by Fermi: NASA Sun Fact Sheet · IAU · NBA Official Rules
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