Forest Moon's Day Cycles

[Hardy]

I know I'm not the first person to notice this, but during ROTJ after the fleet exited hyperspace, we see the Death Star on the night side of the moon. As the fleet gets closer to the Death Star, the Death Star is to the daylight side of the horizon. If Endor had 24 hour days, it would have taken the fleet three hours to reach the Death Star.

This doesn't make any sense. We've seen average speeds of over 1300km/s in ANH. Surely, the fleet would be able to reach the planet very quickly, otherwise Lando wouldn't be so surpised to find out that the Empire knew he was coming.

I've taken measurements(with 28" TV and a centimeter ruler, and assuming that the moon is 12500km in diameter). Comparing the actual diameter(12,500km) of the moon and the apparent diamater when you scale it next to Admiral Ackbar's head(.15 to .2 meters). The fleet therefore dropped out between 60 and 80,000km from the moon.

I've also taken indirect measurements of the speed of the Millenium Falcon based on the growth in the diamter of the moon as viewed from the cockpit. The planet grew by 1/14th it's own dimater in a second at a constant rate. Knowing that its "growth" is proportional to the rate that the fleet is getting closer, we can infer that the Falcon was travelling at roughly 900km/s. At that speed they should have reached the moon in no more than two minutes.

The Forest Moon has a horizon that moves very unevenly or it has 16 minute days. The former seems to work better since we see daylight on the moon that lasts much longer than 16 minutes. It really hurts the brain to think of how the horizon moves the way it does. But this does suggest that Endor doesn't have arbitrary 24 hour days.

[Tychu]

Its a moon orbiting a gas giant. Endor may not even have a day and night cycle because of this. Its hard to determine since Real life humans dont have a civilization off of our nice little Green and Blue Ball. We dont know how a planet really effects a moons day night cycle. Our moon is so weird that it rotates the same amount of time as its revolution.

You cant really tell how long the day night cycle is if you dont really know how long the battle of Endor was. It was night before and after the battle but was day during the battle. How long was the battle!?!?!

[McC]

Its a moon orbiting a gas giant. Endor may not even have a day and night cycle because of this. Its hard to determine since Real life humans dont have a civilization off of our nice little Green and Blue Ball. We dont know how a planet really effects a moons day night cycle. Our moon is so weird that it rotates the same amount of time as its revolution.

Of course it does -- we see the AT-AT/Luke & Vader scene at night. We see the Ewok village at night.

As to the OP, you apparently can't use on-screen distance/size measurements to determine anything, since you need to know a little something about the angles involved and the only way to do that is to know about the lens use, which we are "not allowed" to use, since it's not part of the actual filmed world. Ratios might be allowable, though...I don't know. You'd have to ask one of the SoD gurus, like IP or Connor.

[Hardy]

As to the OP, you apparently can't use on-screen distance/size measurements to determine anything, since you need to know a little something about the angles involved and the only way to do that is to know about the lens use, which we are "not allowed" to use, since it's not part of the actual filmed world. Ratios might be allowable, though...I don't know. You'd have to ask one of the SoD gurus, like IP or Connor.

I never use distance to the lens, of coruse, since I don't know the lens settings.

But if there is an object with a known size standing between the camera with another object of a known size in the backround, you can determine the distance between the objects by directly scaling(as in saying that a planet next to a peron's head is less than a meter across) the object in the backround to the object in the foreground. You divide the known width of the object in the backround by the apparent width as compared to the obejct in the foreground and you have your distance between the two objects.

But you may have a point since I've never seen this method endorsed or used by scientists before. It may not be as simple as I think it is.