Martin Grant

“They are aficionados at this point, and are hoping to see the green flash at sunset. Apparently Earth’s gravity, or atmosphere, they argue about which, bends the light from the sun in such a way that just before it dips under the horizon and disappears, the Earth is actually physically between the observer and the sun, but the sunlight is curving around the globe because of the atmosphere, or gravity, and as blue light curves more than red light, this curve around the Earth splits the light as if passing it through a prism, and this means that the last visible point of sunlight turns, not blue, which would be too much of a bend and too much like the sky’s color, but green, said to be a pure brilliant emerald green. “This we have to see!” Aram declares. Badim agrees. “Strange to be as old as we are, and see it for the first time.” He turns and calls to Freya. “Girl, come see this green flash that may occur!” “You’re not that old,” she says to him. “You’re like the hundredth-oldest person in the ship.” “Well, even that would be old, but in fact I think I’m down to about fifteenth now. But let’s stay focused on the sunset. I’m told when the sun is three-quarters gone, you can look at it without damaging your eyes. Not for long, mind you, but long enough to see the green flash when it comes.”
― Kim Stanley Robinson, Aurora