1 light-year is a unit of length that represents the distance light travels in 1 year. The closest star, Proxima Centauri, is 4.2 light-years away from Earth. How much time would it take for light to travel from Proxima Centauri to Earth?
- 8.4 years
- 1 light-year
- 4.2 light-years
- 1 year
- 4.2 years
