Astrology question about lumens and moonlight, please help =)

Hello folks,

I wonder if any kind soul could help me out with what to most people will
seem like realllllly... strange question. If you were trying to fake a moon
from 2000 metres away, what sort of size "fake moon" and lightsource would
you need? I've gotten as far as to work out that the "fake moon" would have
to be about 2 metres or so in diameter - as for the light wattage (lumens?)
I'm completely in the dark.

If you want to know why I'm asking this question, it's because I'm an
amateur entomologist - basically I catch, record and then release moths.
Migrating moths fly at about 2000 metres high (to catch faster air
currents), ergo, to get them to land near you to record what's going on you
need a "fake moon".

Many thanks,

Johan