Course Description
Humans have always wondered if we were alone in the universe. We were fascinated with the unknown and what creatures lurked in the far away corners of the map and beyond the stars. It was not until recently that we, as a species, had the technology to really intensify and standardize our search. In this course, we will be exploring both the real and fictional search for aliens by humans. From popular television shows to NASA’s real life exploratory missions, students will learn the methodology and the science behind searching for alien life as well as the philosophical implications and other ramifications of being successful in our search.
Week 1: Introduction to Exoplanets
NASA, in the first part of this web series about exoplanetary science, tells us of the history of exoplanets from the very first one in 1995, to the Kepler telescope’s current finds. The 5 methods of discovery, radial velocity, transit, gravitational microlensing, direct imaging, and astrometry are all explained. In addition, NASA provided their data on how many planets have been discovered through each method. It also details the limits and constraints the current technologies have.
Although slightly outdated (NASA archived this page), this web page does contain the aims of exoplanet research. The main takeaway is to find how rare or typical earth is and explicitly what are our goals and aims of searching for exoplanets. The third “reading” is an interactive online atlas that shows artistic representations of exoplanets along with some of their properties. It can be downloaded here.
Another interactive bit is on zooinverse.com on their Planet Hunters site. Planet Hunters will give students the opportunities to participate in this exciting world of astronomy from the relative comfort of home. It also contains miniature lessons that explain in an accessible way more about the transit method of exoplanet discovery.
Week 2: Searching for Aliens and Habitable Zone
The Drake Equation and the Seager Equation
Both of these readings discuss mathematical equations written by scientists that try to quantify humanity’s chance of detecting life on other planets. Looking at both, it’s important to note the differences in both Drake’s and Seager’s approaches. The takeaway here is how much of a chance do we have of finding life if it’s out there.
These lecture notes from a professor at the University of Maryland provide an excellent introduction to how we define the habitable zone. He also goes into what are some of the detractions of having such a limited definition of habitability. Some of his concerns were addressed in Seager’s development of her own equation.
Are we even looking in the right place?
This video and this peer reviewed article apply the law of averages to help us inform our search. Developing from the fact that the Earth is our only data point, we can expect that we are a member of the largest type of intelligent population. But a typical intelligent life form wouldn’t be like us. The article explores instead what “typical” intelligent life might look like.
This is a cool interactive calculator that determines the habitable zone of any star depending on the specifications that you give it. It is a good illustrative of how much the habitable zone moves as the star become brighter and larger over its lifespan.
Week 3: Astrobiology
Dartnell, Lewis. Astrobiology: Exploring Life in the Universe. New York, NY. Rosen Publishing Group. 2011
It’s an introduction to the emerging field of astrobiology. Dartnell gives some basic geological, and biological requirements for what astrobiologist would consider habitable planet. The whole book really is required reading. Particular focus should be put on the Exo-Solar and habitable zone chapters as they elaborate on what conditions habitability is based on and gives possibilities on what life should look like outside our solar system.
Week 4: Extremophiles
http://conference.astro.ufl.edu/STARSTOLIFE/science_final/talks/janotpacheco_e.pdf
Using the new understanding from last week’s reading, we are now equipped to understand at the extremes that life can exist at. This presentation is from an astrobiology conference by a group of biologists that are proposing an extension to the habitable to include temperature ranges that are known to harbor extremophile life on earth.
This article really focuses more on verifying the panspermia theory. The panspermia theory hypothesizes that life originated somewhere else in the galaxy and was transported to Earth by a meteorite. The authors discovered that very small populations of extremophiles could survive the extremely unhospitable conditions involved with being launched into and traveling through space, as well as crash landing on another planet. The hardiness that is demonstrated by this study opens up many possibilities to the harsh conditions that these simple lifeforms could withstand. Their resilience means that although they would be hard to detect, life could be on many more “unhospitable” planets than previously thought.
The X-Files season 4 episode, “Tunguska”, deals with some elements of the panspermia theory. Alien bacteria is found on a meteorite and it turns out to affect humans in a very dramatic way. They name the ensuing disease the “black virus.” Ironically enough, the show got it right that some bacteria could survive the perilous journeys between planets. It derived inspiration from a real-life meteorite, ALH84001, whose surface contained bacteria-esque features and excited the scientific community for some time.
