"It is only with the heart that one can see clearly, what is essential is invisible to the eye" Antoine de Saint Exupery.
The lower or darkened planes are six in number, each one is half the size of our moon, so one might say they are 3 moon's in size total. Every day (earth time) people are leaving the dark realms, and going into the light, it is their choice, to do so, they must bow, and cross over willingly, and believe that Jesus died for our sins upon that cross.
In the fifth plane of darkness are prison cells where some people go as well, usually to serve out sentences given to them while they were yet on earth. If they were truly guilty, they must first complete the sentence before re-evaluation. when someone dies before they have served time here in jail, they will stay in this lower plane jail until the sentence has been carried out. The lower the depth, the darker it is, the fifth plane where jail cells hold murder's the light is very dim, and the farther one goes into the lower realms, the depth away from the Light of God, becomes pitch black, don't know exactly who or what is down there, but they must have been pretty evil while on earth to be there in that place.