The class where I intern is about to start their unit on astronomy and I know one of the sub-units is on the moon. I found a simulator through the University of Nebraska-Lincoln that provided a lunar phase simulator.
I, personally, think it is a pretty fantastic simulator. It offers numerous variables that the user can adjust, including ones that make figuring out what the simulation is showing easier to understand. The simulation can be sped up or slowed down, additional panels can be shown or hidden that depict the moon phase and horizon diagram.
I think the powerful thing about a simulation like this is that, as stated in the National Science Teacher’s book, is that simulations can be used to give students the opportunity to see and participate in a scientific event that they may not be able to do on their own. Sure, students could in theory go out and observe the moon through its phases and plot them throughout a lunar cycle, but with weather, light pollution, bed times, homework, etc it becomes a much more difficult plan to carryout. Not to mention the time necessary to observe a full lunar cycle would make the unit too long.
A simulation like this one, allows students to participate in something out of their reach in a meaningful way. As long as we as teachers, preface the use of simulators in a way that gives students the information they need to understand the simulation program, the information to introduce them to the process/procedure being simulated and follow-up with them during the lesson, the use of simulations can prove to a useful tool to bring that which would normally be out of reach to our students to their fingertips.
That is not to say there aren’t negatives to using simulations. Teachers need to gage the complexity of the simulation they wish to use and see if it matches the level of their students. A simulation that is above level will be nothing more than an entertaining game while one below level will encourage students to tune out the information. There is certainly a sweet spot as far as finding an engaging meaningful simulation.
Also consider how difficult the simulation itself is to use. The one I found is a bit more sophisticated some of the PHET simulations provided by the University of Colorado Boulder (https://phet.colorado.edu/). If I am going to teach middle school science, I would probably see what the PHET site had to offer first since they categorize their materials by grade level.
The textbook also discussed that instructors need to make sure to preface the simulation with useful information regarding scale, color schemes and dimensionality. Make sure your students know these are 2-D simulations in a 3-d world and that color schemes used are more than likely for emphasis versus what they might actually look like in reality.
Like so many other tools that are technology based, the use of simulations can be a powerful teaching tool as long as the simulations are well vetted before being used.