The sun is not special. I know that’s a churlish thing to say about everyone’s favorite celestial body, our planet’s blazing engine and eternal clock, giver of light, life and spectacular Instagram backdrops. Awesome as it is, though, the sun is still a pretty ordinary star, one of an estimated 100 billion to 400 billion in the Milky Way galaxy alone. And the Milky Way is itself just one galaxy among hundreds of billions or perhaps trillions in the observable universe. Then there’s Earth, a lovely place to raise a species but, as planets go, perhaps as unusual as a Starbucks in a strip mall. Billions of the Milky Way’s stars could be orbited by planets with similarly ideal conditions to support life. Across all of space, there may be quintillions of potentially habitable planets, or even a sextillion — which is more than the estimated grains of sand on all of Earth’s beaches.