"The Wall" is what the Zheroshians call the Asteroid belt that surrounds them and their planetary neighbor, Nahbor. The asteroid belt is wide, about three quarters of a light year, making it difficult to get around. The asteroids are rich in Stabilizer fluid and sometimes that the Zheroshian's mine for energy. Sometimes the fluid gets exposed, and it reacts to the naturally occurring radiation creating rikta energy. This sudden burst of energy sends asteroids in a different direction.
The Zheroshians created a navigation system that picks up anomalies with the asteroids to predict when they will move out of place. They have used this to their advantage when the raiders attack. So far, none of them survive the wall.
Feel free to download the card to the left and keep it in your collection of pictures. If you upload this to your own website, you must link to this site.