At a high level, the image was rendered using a sphere with a picture of the Earth texture mapped onto the sphere then rotated to get a good angle with sufficient land mass visible. Next, I placed the sphere on a reflective surface that is a little darker to give nice looking reflection of the Earth. Lastly, I put a background in the back full of stars. I placed a light from the top and two more in the bottom corners so that the Earth is fully visible but we also get a nice shadow effect below it.