How to properly clear the canvas in this case?

Question

JavaScript

Good day.
I tried to implement a "likeness of starfall", but after the tail of the circle, the strip is not cleared, and a trace remains. How to implement correctly the semblance of such an effect (what would be the tail behind the circle, and there would be no strip)?
Actually here:
https://jsfiddle.net/dt4gpvyr/2/

Answer 1

Clear the canvas completely and draw the tail with a gradient