Exoplanets have been in the news a lot lately. NASA's Kepler Space Telescope, designed to search for earth-like planets outside of our solar system, has already discovered over 3,000. Many of these planets are in the so called Goldilocks zone. Not too hot, not too cold; just right for life. New estimates suggest there may over 40 billion earth sized planets in the Milky Way.
Scientists have been debating the probability of life in the Universe for many years. But Kepler shows that planets orbiting stars are far more abundant than once thought. There are over 100 billion stars in our galaxy, the Milky Way. But that's just the beginning. There are around two billion galaxies in the universe. Mind numbing!
Astronomer Frank Drake proposed an equation in 1961 to estimate the number of advanced civilizations in the universe, long before the first exoplanet had been discovered. Using the "Drake Equation," astronomers now estimate there are between 1 and 72,000 advanced civilizations in the Milky Way. Multiply that by two billion to get civilizations for the entire universe.
I've been following this research for many years, and I love imagining what life in other worlds must be like. Then last summer I had a realization. If there's so much life, where the heck is everybody? Turns out I'm not alone. Enrico Fermi of the Manhattan Project often discussed this issue with colleagues over lunch, and thus the "Fermi Paradox" was born. Maybe advanced societies only communicate for several hundred years before collapsing. Perhaps intelligent life that invents technology is far less likely than we think. There are many possibilities. After all, even majestic whales with their massive brains aren't known for their technological innovations.
New NASA telescopes will detect indicators of organic life on exoplanets, so the answer to one of humanity's biggest questions - Are we alone? - is within reach. If the answer is 'no', whole new worlds of wonder open before us and even the wildest science fiction movies will seem pedestrian. But if we are, against all odds, alone, I expect an equivalent amount of wonder.