I added a sphere to the scene. Then use a cloner object on it. then set it the cloner to Radial with a value of 50 to create 50 Sphere. I then grouped the Cloner & sphere into a Null object.
I add a Mograph Tracer object to the scene and set it to tract the Cloner object to create a spline that trace the path of each sphere in the cloner object. I then use the Tracer object to sweep Nurb to create the the tail for each sphere as it animate. I animate the null that contain the cloner object to cause the tracer object to give me tail and twist.
From the Previous step I then Added 3 lights and set up my camera and camera target. I added a Light blue to Sphere to represent the planet in the background. I set the Compositing tag of the sphere and unchecked the "Seen by Camera" option.
I then adjust and play with the camera and Lights until I have what i want and render it.
The background use is From here :http://www.free-picture.net/albums/space/earth-from-space-on-winter.jpg
This is a render of the scene with out the background.
Note that the Background object is not the source of reflection.
Background object do not cast reflection...
I added an Invisible planet in to scene as explained in the Previous step. The Compositing tag allows me to place an abject that cast reflection or shadow in a scene with out it being visible in the Render.