How much time does sunlight take to reach the Earth?

Correct answer: 8 min 20 sec. Light travels about 150 million km at about 300,000 km/s, so sunlight takes about 8 minutes 20 seconds.

Background: The exact time varies slightly because Earth’s orbit is not a perfect circle.

• 3 min 7 sec: 3 min 7 sec is too short.
• 8 min 50 sec: 8 min 50 sec is slightly too long.
• None of these: “None of these” is incorrect because 8 min 20 sec is correct.

Did you know? Moonlight takes only about 1.3 seconds to reach Earth.

Memory trick: 8 min 20 sec.