Light-time is the product of the speed of light in a vacuum and time it takes light to travel a certain distance in space. It is most commonly used in light-years to calculate interstellar distances.
Common units of light-time
The light-second, light-minute, and light-year are the most common light-time units used.
|1 Light-second||0.0020 AU|
|1 Light-minute||0.12 AU|
|1 Light-year||63000 AU|
For Mars, light time translates into communication times. For example, it could be said that at its closest Mars is about 4 minutes away from Earth, while at maximum separation it is about 20 minutes away.
- “Light-Time.” n.d. In Marriam-Webster Dictionary.