Can I scale 1 image in animation to bigger and still maintain the visibility of the image in front of it? I have 3 images, 1 in front of the other and want to make them move and scale in animation:


image is background - just space with a few galaxies,
image is the earth,
image is a little alien who is waving his hand.


I want the background to be still, i want the earth to scale bigger towards the "camera" and i want the alien to scale smaller and smaller towards the earth. 

My question is: can I make the earth appear bigger and bigger in animation to the point where it will cover the entire screen WITHOUT it "moving" in front of the alien image? I want the alien to be constantly visible waving his hand in front of the expanding earth, so it looks as he is falling towards it, but am afraid the image of the earth will at some point move in front of him! 

Is it even possible for an image to move in front of the front one if it`s scaled "to much"? 
(I'm very inexperienced and realize this question might be very funny...)
So, basically: You can achieve the wanted effect on different ways. You could try it via changing location and so on, but the easiest way is: just scale the images and set key animations.

Go to the start frame, select the image of the e.g. earth. Press "S" and scale it to the wanted start size. Now press "I" and choose "Scaling" from the pop-out-menu. Now go to the next frame you want to define (for example the last one) and repeat the steps. Same you can do for the alien. Just make sure to have a small space between alien and earth for avoiding weird overlaps.

For more information about animating, google a bit ;)

I am not sure whether I understood your last question right (^^) but as scaling just affects the size and not position, overlapping another image by "overscaling" shouldn't happen. Provided there are really only images (that have no depth). Object can overlay each other if the depth becoms too big, logically.

Hope it helped :)
Greets, Jaspa