On Rendering the Sky, Sunsets, and Planets

Inspired by a photo of the Space Shuttle Endeavour at sunset, a developer built a real-time atmospheric scattering shader that renders realistic skies, sunsets, and planetary atmospheres in the browser. Using raymarching combined with Rayleigh and Mie scattering plus ozone absorption, the shader accurately simulates how sunlight interacts with air to produce Earth's blue sky and vivid sunsets.