The Drake Equation: Are We Alone in the Galaxy?

by Connor Lynch '17

N = # of observable civilizations currently existing in the Milky Way [image via]

During November, the odds of an intelligent civilization existing somewhere in the Milky Way shot way up. NASA’s Kepler spacecraft has been able to identify and analyze a vast number of exoplanets across the galaxy by detecting micro changes in incoming light due to planets passing in front of their respective stars. This is referred to the “transit method” of finding planets. The latest discovery from the new data of Kepler’s images confirms that there may be an Earth-sized planet in the “Goldilocks zone” of nearly 20% of sun-like stars in the galaxy. This would put the number of possibly habitable worlds up to nearly 40 billion. The search now officially commences for a twin Earth, a planet with conditions extremely close to that of Earth which hopefully lies close enough to us to study in detail.

The observations are clear and indisputable but the probabilities have been subject to opinions and speculation. The Drake equation is a mathematical model based in probability that can be used to estimate the number of intelligent civilizations in the Milky Way. At first glance it looks simple but calculating each variable with precision can be tricky for astronomers. However, this discovery only moves the equation a little closer to being solvable, as there are pieces of information that are not grounded in enough data to be made certain. Nevertheless, the data that Kepler has sent back provides a huge stepping stone in the journey to pinpointing exoplanets that harbor life.

[image via]

Turning to philosophy, there is one question that still has to be asked about all of this. Scientists when looking for other worlds use conditions here on Earth as the basis for spotting possibly life-rich planets. But how can mankind only use the biological laws that govern here on Earth to lead the search? As a scientific species, we cannot assume that life across the cosmos must obey the same characteristics of life here on Earth. The discovery of life on another planet, if we could get close enough to analyze it, will be the most moving discovery of mankind, and at the same time possibly the most disconcerting. Let’s just hope we are prepared when it happens.

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1. Overbye, Dennis; The New York Times - Far-Off Planets Like the Earth Dot the Galaxy [Updated November 4, 2013; Cited November 12, 2013]; Available from: http://www.nytimes.com/2013/11/05/science/cosmic-census-finds-billions-of-planets-that-could-be-like-earth.html
   
2. Govert Schilling and Alan M. MacRobert- The Chance of Finding Aliens; in collaboration with SETI - The Search for Extraterrestrial Life [Updated September 7, 2012; Cited November 12, 2013]  Available from:  http://www.skyandtelescope.com/resources/seti/3304541.html