Fermi question · Science
About how many kilometers is Earth from the Sun on average?
Make a fast, defensible estimate before you reveal the reference answer. Think in factors, not exact recall.
What is your estimate?
Your result will appear here after you submit a guess.
Reference answer
Reveal the reference answer
≈ 150 million kilometers
Fermi estimates are judged by scale, so a reasonable approximation can still earn a strong score.
One way to estimate it
Sunlight takes a little over eight minutes to reach Earth.
- Light travel time≈ 8.3 minutes ≈ 500 seconds
- Speed of light≈ 300,000 km/s
- Estimate500 × 300,000 ≈ 150M km
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