The Color of Habitability

Abstract

From life on other planets to virtual classrooms this thesis spans a wide array of research topics all based on how we see other worlds. Our understanding of everything from moon phases, the planets in our Solar System, and exoplanet atmospheres come from our interpretation of light and one day, our knowledge of light will be used as evidence for the discovery of life on another planet. In the time before we scattered rovers, landers, and brave souls across the Solar System we only knew of the planets and moons from the light they reflected from the Sun back to us. We are in much the same situation with exoplanets today. Our telescopes can gather the light from distant worlds but they are too far out of reach to confirm our observations with in-situ measurements. Soon we will be able to gather light from even smaller exoplanets and eventually Earth-sized exoplanets orbiting in their star's habitable zone. As a reference guide to these upcoming observations what better place to compare to than our own Solar System. What we've done is take measurements of planets in our own Solar System and treat them as exoplanets to determine how different surface types can be differentiated. The result is a database of the spectra, geometric albedos, and color of 19 Solar System objects for use as an exoplanetary field guide. A step beyond the field guide is a way to explore worlds only physics and our imaginations are limited by. By using computer models, we can create thousands of planets to determine the physical and chemical stability of any environment. One parameter domain of interest is the role of surface color on a planet's habitability. Different materials have unique thermal properties that either cool or heat a surface depending on their color and the light that hits them. Dark oceans absorb light well and heat up while white sand is highly reflective and keeps cool. Stars emit different types of light depending on their temperature, cool stars are red while hot stars are blue. Blue starlight on a blue surface will stay cool while blue light on a red surface will heat up and vice-versa for red starlight. This results in a complicated relationship for exoplanets and stars that is important to understand if we are to properly plan observations, analyze data, and make predictions with their results. The near future is bright for exoplanet science and as new observations dramatically change our understanding of celestial bodies so too do our methods of communicating that science. At the same time the first exoplanets were being discovered, NASA was developing the use of virtual reality to train astronauts and drive rovers on Mars. Virtual reality (VR) has come a long way since then and immersive VR headsets are now used by a fast growing audience for video games, entertainment, and education. As VR education begins to grow, we need a good understanding of its strengths and weaknesses as a teaching tool. So far, very little is know about how employing VR compares to traditional methods of teaching. By designing a learning activity on Moon phases in VR, we were able to compare the learning gains of students who used the VR version with students who used a desktop simulation or a hands-on activity. This information, coupled with the demographics of the participants, allows for a detailed breakdown of who is learning best under which conditions and plan for further study into the use of VR as a teaching tool.