Cut a large vertical opening on the front of the bottle and two side flaps to create a display window.
Paint the inside of the bottle in dark blues and black, adding white dots for stars once dry.
Paint the foam balls as planets, shaping Saturn’s ring with a pipe cleaner glued around the ball.
Glue the Sun at the bottom, then attach planets upward inside the bottle in correct order.
Add labels to each planet and paint decorative details on the side flaps to finish the diorama.