This is a remix of the base and supports from the LED-Lit Brain by djholt. For detailed instructions see OP's thing here.
I added threads on supports and base, a battery holder for two AA batteries and a mount hole for power switch.
Printed with transparent PETG, normal Prusa settings (0.2mm) and 10% infill (less than OP suggested). Expect a very long print time. Mine took about 33 hours for each hemisphere and 12 hours for the base.