I'll admit... I was in a certain hurry when I did the Earth. And I used a picture for reference (the lighting was obviously different), in order to make the continents look more realistic without using lots of colors. For the moon, I have done similar "monochromatic" things before and tried to push a bit further. Thanks for your comment.
I'm with romanticpixels on this one. There moon looks amazing! The Earth is a little flat, but it could be the lighting, not the palette and shape choices. The lighting isn't quite consistent between the Earth and Moon. Because of how great the moon turned out, I'd consider changing the Earth's lighting to match. But that's the only issue I thought could improve it. Great work, MadMage! Keep it up! 
I love the textures on the moon!