How Comparisons Help Us Understand the Universe
The other night, a few minutes after 8:30 p.m., I went outside and lingered. The surroundings were familiar—the freshly flickering bodega signs, the clusters of people and dogs, the bricks blazing when the sun slants just so on its descent. The sky didn’t look especially alien, either—I often extend my walk home in order to glimpse the world washed the color of a muddy puddle, to stand inside the blue-black darkness just beginning to fall.
But on this particular evening, I wasn’t outside to bask in the bodega golden hour. I was trying to approximate the feeling of high noon on Pluto.
This goes without saying, but: Pluto is not Brooklyn. It is cold; it is dark; it is 4.67 billion miles away. Its differences are legion, and the starkest among them are hard to even imagine. No matter what image I squint to conjure—a body freckled with ice cubes, snow drifts pinning me down—the concept of a temperature sliding to -387 degrees Fahrenheit does not compute.
I’ve never been that cold. Neither have you. But we have both seen twilight, or the moments just after it, and that’s not a bad approximation of what Pluto looks like at its brightest. To help Earthlings imagine life there, NASA has created a website called “Pluto Time.” You plug in your address, and it spits out the exact moment, at that particular longitude and latitude, that the sky above you most resembles the one above Pluto. Any number of other, distinctly-Earthly sensations might jostle for your attention—you may hear wheezing buses or smell meat cooking on a street cart—but visually, you’ll have a proxy for our far-flung solar neighbor.