What is the persistent fear of snow falling

Chionophobia is the extreme dislike or fear of snow.

The word originates from Greek 'chion' meaning snow and 'phobos'
meaning fear, aversion or dread. People with Chionophobia often
understand that their fear is unfounded and weird. However, they
are unable to control it.

Another contributor was the first to answer the question correctly, and in fact,
I learned the answer from that earlier post.  If I could only remember who it was,
I would give them a big shout-out.  Their answer was deleted by a moderator
because it didn't have an explanation with it. 

The masses of the objects and their densities

Some type of thing that was invisible