Lunar/Solar Calculations

[LJP07]

Hi,

 

As we look at the Sun we see it as it was roughly 8 minutes ago. I'm wondering on a Full Moon night, at a usual time for maximum sunlight on the moon, how long does it take for the light to go from the Sun to the Moon and reflect back into our eyes? So when we look at the Moon, how many seconds/minutes ago have we actually seen it?

 

Also, does the spherical nature of the moon create different times for light to reach our eye. For example in a Full Moon, the left/right center parts are further away from the observer than the bulge we see at the center. So what's the difference in time it takes for light from the tip of the bulge to reach our eye and the furthest peripheral area that are further away from the observer?

 

Just a few questions that are bugging me.

 

Thanks

[Roadam]

For the first part: the time is still roughly 8 minutes as sun is averagely about 150 million kilometers away while the moon is circling at 0.38 million km. That is just about 1.3 seconds for the light to reach us from the moon.

 

Radius of the moon is around 1700km so thats about the difference in the path of light. That gives about 6 miliseconds.

[LJP07]

Thanks.

 

What about Jupiter and Neptune?

[Roadam]

Quite longer, you can check it at wikipedia anyway.