* Distance: Neptune is about 2.8 billion miles (4.5 billion kilometers) from the Sun.

* Speed of Light: Light travels at approximately 186,282 miles per second (299,792 kilometers per second).

Calculation:

1. Convert miles to seconds: Divide the distance by the speed of light: 2.8 billion miles / 186,282 miles/second = 15,000 seconds (approximately).

2. Convert seconds to hours: Divide the seconds by the number of seconds in an hour: 15,000 seconds / 3600 seconds/hour = 4.17 hours (approximately).

Therefore, it takes light approximately 4.17 hours to travel from Neptune to the Earth.