A Time Odyssey 2 - Sunstorm (spoilers)

[AcesHigh]

I am reading this book right now... little less than half the book.

They are building a railgun at the moon to launch material in space, which will be used to build the giant shield to protect the Earth from the huge sun blast.

And then I wondered... couldnt the moon ITSELF be used as a shield?? It would be MUCH more efficient than the thin shield they will build (which will only block visible light, but no xrays or gamma rays.

Of course... the moon would have to be MOVED and positioned in some geostationary orbit.

I am not good at mathematics... I know it would be REALLY hard to move the moon out of place in only 5 years... but I guess that using a large quantity of anti-matter of even fusion explosions, you could move the moon, just like a rocket using nuclear pulse propulsion.

So the questions for those who like some math:

1 - is there any position where the moon would be able to shadow the WHOLE Earth? I think the biggest problem of my analogy here is that while getting the moon closer to Earth, a viewer on Earth would see the moon blocking most of the sky, but since the sun is so big and so distant, the moon shadow size wouldnt really change (it would only change if the light source was close to the moon itself). Can anyone confirm this?

2 - would it really be possible to move the moon using nuclear pulse propulsion, fusion or anti-matter? How much energy would be necessary to move it closer to Earth (if there is any point in it at all, like mentioned in #1). Well, at least in Larry Niven´s Ringworld, they move the Ringworld, which is 90 million miles in diameter and 1 million km in width, using ramjets.

[AcesHigh]

forget it. My mind started working a bit and I realized that since the sun is bigger than the moon, and since all of the sun surface emits light, it doesnt matters the moon distance, there will always be parallel light emited from the sun that will be able to hit Earth, since the Earth is also bigger than the moon.

The system would only work if the sun was a POINT of light, or at least smaller than Earth.