Render the terrain. (No atmosphere? Turn off the atmosphere.)
Start a new terrain. Move the camera into space, so nothing but black is rendered. Copy the camera's coordinates. Load the object. Paste camera's coordinates to the object coordinates. Move the view back so the object shows up in the preview how you want it.
Now, use the default shader on the object. Load the terrain image into the color channel. You'll want to set it to Camera Projection. The color can be influenced by adding a shader to the blending input. This should work, but it's not a true reflection like you wanted.
