The Sky Project Comets

By: Corey Everrett, Aaron Day, Andrea Melvin, Helen Button

Throughout history, people from all corners of the globe have been watching comets. From priests in classical Greece, to early modern astronomers, to missionaries in New France, people have questioned the origins of these seemingly miraculous flashes in the night sky. Were they signs of divine anger or were they perhaps omens of wars, plagues, or natural disasters?

Classical philosophers theorized about the shape and composition of comets. In the sixteenth century, cosmologists began to chart the paths of comets and measure their positions in the sky. Always, philosophers wondered about their meaning, until in the late seventeenth century, astronomers who watched the sky with telescopes began to consider them from a scientific perspective, as phenomena which originated in nature and obeyed its laws.

Astronomers continue to watch the skies today, although they make use of very different technologies. In fact, Western researchers have a network of all-sky cameras across Southern Ontario, allowing them to chart the paths of comets and estimate the locations in which they land. Have you seen a comet?

The group decided to use a globe of the world, Google Earth, and a projector to give viewers a unique learning experience.

Google Earth is an electronic mapping application that can allow historians to interact with the spaces in which history took place, and to visualize changes to the landscape over time. In a world where we rely on GPS and online maps to find our way, Google Earth can make the past more immediate to today’s audiences.

Viewers stand in front of a large screen which has the program Google Earth projected onto it. The viewer can interact with the exhibit by pushing one of four buttons embedded into a globe of the Earth. When a button is pushed, Google Earth zooms to that location on the Earth and displays content related to a comet that was viewed at that place, sometime in the past.

Users had one of four historical comet sightings to choose from and could learn how people from different parts of the world and different times interpreted a similar event.

To create this exhibit, the group first attached four SPST switches to specific locations on the surface of a globe. Four wires ran from the backs of the switches, through the inside of the globe, and then combine in a main cable which attaches to a small computer called an arduino board.

The arduino board functions by constantly watching each of the four switches. When one is pressed, the arduino board forwards that information to the main computer running Google Earth.

The computer receives these signals via USB. Custom written Python code installed on the computer watches the USB port. When the port receives a signal that a switch has been pressed, it tells Google Earth to open a custom written .KML file which contains the GPS coordinates in Google Earth as well as supplementary information for that Comet.

Components used:

• 4 SPST switches (buttons)
  

• Arduino Board
  

• USB cable

Computer Programs used:

• Python (custom code)
  

• Google Earth
  

• Custom written .KML markup