Well, it’s 3 am and I’m gonna break this thread to throw my best guess in because I feel like it.

Let’s define X and Y coordinates as X and Y, and throw in a T for Time. We move in a sine and cosine wave on both axis to generate a circular motion, so

X = sin(T)

Y = cos(T)

Step 1: T = 0. Using command blocks: Spawn an invisible armor stand holding a snowball, that floats upwards (probably has a levitation potion effect or something) at (X,Y)

Step 2: increment T by a lil bit

Step 3: spawn another snow ball wielding stand at T+[increment]

Step 4: repeatedly repeat steps 2-3.

Optional: create the dual helix shape by duplicating it, but adding 180°/Pi Radians to T.