Generally speaking the astral body and I emerge from the physical and etheric bodies during sleep. Man's I and astral body are in the spiritual world while his ether- and physical bodies are in bed.
Also generally speaking one can divide the astral body or soul into the sentient soul, intellectual or mind soul and the consciousness soul. One must always bear in mind that these divisions overlap somewhat - there are no strict borderlines. (For explicit explanations of how the human being functions see: R. Steiner's 'Theosophy').
Now sleep can also be divided into three states: the dreamless sleep, dreaming and sometimes sleepwalking or -talking. The dreamless sleep is subject to influence on the sentient soul, the dreaming state to influence on the intellectual or mind soul and the action state to influence on the consciousness soul. When the influences on the mind soul and consciousness soul have taken effect, man is strengthened and energized; he has taken from the spiritual world the forces he needs for his life during the next day. The influence on the sentient soul sends him to sleep when it has become exhausted by the impressions of the physical world (colors, lights, objects, pleasure, pain, sympathy, antipathy). And the same force, now operating in the opposite direction wakes us again.
These influences or forces working on our soul parts can be connected with the planets. If one wished to make a diagram sketch of what happens, it might be done in the following way, but this is meant only as an indication.
The lower loop indicates the waking state and the upper loop the sleeping state.
The force which works on the sentient soul at the times of going to sleep and waking up was given the name Mars in ancient times. The force which works on the mind soul after one has gone to sleep and again before waking up (two different periods!) was given the name Jupiter. This is the force which drives the world of dreams into the mind soul. The force which works on the consciousness soul during sleep and under special circumstances would make one into a sleepwalker was given the name Saturn.
When one wakes in the morning it is the sentient body that enables sense impressions to be received; but what we experience and feel inwardly as the result of these impressions is caused by the sentient soul. So in the morning one receives the impressions of the outer world in the sentient body and this arouses feelings of pleasure or pain in the sentient soul. So one can say that the first influence on the sentient soul after waking is caused by the force called Venus.
Then there are influences which enables man not merely to stand gazing at the tapestry of the sense world, but to form thoughts whereby he combines the external impressions in his mind soul and makes himself independent of the influences of the outer world. These are the influences of Mercury. Mercury influences the mind soul during the day as does Jupiter during the night.
During the waking state there are also influences on the consciousness soul. When we first have feelings in the sentient soul, then work them over in thought and turn again to the outer world and relate ourselves to it by passing over to deeds - then we are given over to the consciousness soul. The force which enables us to relate ourselves to the outer world again is called Moon.