Comet 15x brighter than moon coming soon

[SvennoJ]

happydolphin said:

Troll_Whisperer said:

The article says it will be clearly visible during the day, so it must be pretty bright. The moon is just barely visible during the (sunny) day.

Makes sense.

The moon is very visible during the day, especially in November.
Anyways what do they mean with 15x brighter. I don't think it will be total light received on earth compared to the moon. Brightness at the center probably, and since it will be tiny compared to the huge disc of the moon I doubt it will do much for illuminating the night.
Both are visible by reflected sunlight, although the ice from comets is a lot more reflective it can't compete with the area surface of the moon.
It should be a cool sight anyway, I wonder how long the tail will be seen from earth.

Actually I'm wrong about the size comparison, comet's tails can easily be wider then the earth's diameter and extend for the distance between the earth and the sun, yet it's all about density in the end. What part of the tail is dense enough to be visible.
And even an earth sized reflector at that distance is still tiny, see venus transit. (Venus being the size of the earth and only a pin prick, while the moon covers the whole sun)