Select from a variety of programs that cover CCGs including inquiry-based use of digital data. We've just added a program that covers how astronomers know what they know, by measuring data from the sky. Starting with an investigation of the digital measuring tool, we end by working through a series of digital data that illustrate how objects are found, identified, and tallied. We can adapt this to almost any grade level and to a variety of time frames. Info will be on our web site shortly.
Prep work in advance, and scheduling outreach in advance, are still important.
Simulate the parallax situation by holding out one hand with extended finger at arms length, move finger side to side about 4 inches, note how much of the background it appears to sweep across. Now, keeping your head steady, move your finger right in front of your nose, and sweep same 4 inches back and forth. Compare how much of the background your finger appears to cover. In a sealed, dark room, with no internal sources of photons nor any photons leaking in, there's nothing to register on your eyes.