An interesting and forgiving project - even if implemented badly you can get nice results. 

The stars of the show:-

- Strontium Aluminate:

When strontium aluminate is charged by light, its electrons jump to a higher energy level. To return to their base state, they must release this energy as light. The "Forbidden" Nature: Returning to the ground state requires a change in electron spin. Quantum mechanically, the probability of this happening is extremely low, making the transition "spin-forbidden".The Result: Because the transition is forbidden, the electron gets stuck, releasing energy very slowly. This slow release creates the bright, hours-long phosphorescence (glow) that strontium aluminate is famous for.

You will need to get the good stuff, not cheap "Glow in the dark powder"

Regarding handling and safety - think powdered glass, and handle appropriately.

-A Frikken Laser: 

405nm Laser (UV), this is a tricky one, look for an engraving laser, there will be lots of lies about its power but as long as it is a focused engraving laser at 405nm you should be OK. 

Some will have heat sinks, some will not, we will use PWM to drive the laser, in my experience the laser will not be pushed too much and the heat sink is not required.

Regarding handling and safety -It's a Frikken Laser! Be very very careful, use appropriate glasses and observe safety measures.

One thing people miss is that it is "a focused laser" that makes it safer in that it will only "burn" when focused at a specific distance - the distance to our Strontium Aluminate, after that it will diverge and become less blinding :-) Seriously though, please be very careful, especially at the early stages of the project, safety glasses are relatively cheap on Amazon.

-ESP32 dual core:

A fantastic microcontroller, the second core is vital for handling the gimbal motor while the first core handels WiFi coms and other stuff.

-Nema 17 stepper motor - and a suitable stepper driver board

A highly popular stepper motor. At least a 1/16 micro step driver  board should be used.

-A Gimbal Motor - and a suitable driver board (DRV8313)

Brushless motor and board, not cheap but getting cheaper. Can do lots of things using the following;

-AS5600 12-Bit Magnetic Position Sensor

a highly popular, low-cost contactless magnetic rotary position sensor. Instead of using physical gears or wipers like a traditional mechanical potentiometer, it uses the Hall effect to calculate the absolute angle of a diametrically magnetized magnet placed near the chip

-SimpleFOC:

This is the big star of the project! Cant say enough good things... Thank you SimpleFOC!

A community-driven, open-source initiative with the aim of demystifying Field Oriented Control (FOC) for user-friendly motor control. The project aims to provide well-documented, modular, and cross-platform solutions both in software and hardware.

Big shout out to using a piece of hard drive platter as the laser mirror, it's perfect. 

A physical overview:

In its simplest form the mechanism is a laser X - Y stage inside a full sphere. 

The 45 degree mirror driven by the gimble motor can do a full 360 scan and along with the base stepper moving the whole thing (only 180 degrees of movement is needed), almost all of the sphere can be hit.

 A portion of the south pole gets blocked by the supports and base stepper motor but its size is relatively small.

If you can imagine this, you will see that it can project / scan to almost any surface around it. 
Scanning to a flat surface works well but needs image transform for bigger angles.

The whole assembly :

The moving bits:

1-AS5600

12Bit Magnetic Encoder Magnetic Angle Measurement Sensor Module

Very affordable module - currently 8 Euro for two, used with the simpleFOC library and a brushless drive board to control...