The shadow object is where the moon shines a "shadow" in opposite of the suns light. In nature there are always opposites, North and South, East and West.....Round or Flat! There is currently no better explination for the use of the word "shadow"
I belive this is what the shadow looks like when observed though a hydrogen lens microscope.
You ready?

The image is so small because the telescope was so powefull.
Do not doubt the power of the microscope!!