Simulating the Kepler Space Telescope with an Exoplanet Motion Model and Detector

Thanks to 20th century science fiction, we’ve long assumed there are planets orbiting other suns light years away, but how do we know that’s actually the case? As it turns out, humankind only confirmed evidence of these exoplanets in 1992, based on minuscule variations in a star’s brightness as the planet passes in front of it. To illustrate how this method works, Marcin Poblocki created his own shining sun and dual-planet setup, in addition to a corresponding detector unit.

The planetary arrangement is controlled by an Arduino Nano, along with a BYJ48 stepper motor driver. This spins the planets using a gear drive system. Planet positions can be adjusted via holes in rotation arms, and speed can also be varied by a potentiometer.

The detector part of the apparatus employs a second Arduino Nano and an LDR to detect how much light is transmitted to the “observatory.” It outputs readings over serial, which can be graphed nicely in the Arduino IDE’s Serial Plotter tool. This data can be stored in an SD card for later analysis as well, providing a mostly sinusoidal pattern that you’d expect from such a system.

While certainly not as sensitive as the Kepler telescope that's used to find actual exoplanets, Poblocki's build looks like a great teaching tool to explain how planets move and how the can be observed indirectly from Earth. Check it out in action via the video below!