Final answer:
One way of identifying the night end of the MK-13 MOD O distress signal in total darkness without the aid of artificial light is by the sound.
Step-by-step explanation:
One way of identifying the night end of the MK-13 MOD O distress signal in total darkness without the aid of artificial light is by the sound.
By using your hearing, you can listen for the sound of the distress signal which will be louder when you are facing the night end.
This is possible because sound travels in waves and can be detected even in darkness.
For example, if you are standing in an open field and you hear the signal louder from the left side, then that would indicate that the left side is the night end of the signal.