Venus
Simulated by Astrosyo
About this page
Above is a GPU-accelerated, real-time visualization of Venus, Earth’s nearest planetary neighbor and the brightest natural object in our night sky after the Moon. Unlike Jupiter’s banded clouds, Venus is cloaked in a feature-poor but dynamic global cloud deck of sulfuric-acid droplets above a thick CO2 atmosphere. This simulation emphasizes phase lighting, a high-albedo cloud layer, and the planet’s famously slow, retrograde rotation.
What you’re seeing
Venus rotates backwards (retrograde) once every ~243 Earth days, while it orbits the Sun in ~224.7 days—so a Venusian day is longer than its year. Despite the slow spin, the upper atmosphere super-rotates, circling the planet in just a few Earth days. In this model, subtle moving textures hint at that high-level wind flow without simulating full fluid dynamics.
The thick cloud layer reflects most sunlight, yielding a bright disk with pronounced phases as Venus swings around the Sun from our viewpoint. Lighting comes from a fixed “Sun,” and the shader applies soft limb shading and gentle forward-scattering to evoke the hazy atmosphere. Because the visible cloud deck hides the surface, no continents or land features are rendered.
Observing Venus
Venus is usually seen shortly after sunset or before dawn as the brilliant Evening or Morning Star, often reaching magnitude −4. A small telescope will reveal its crescent-to-gibbous phases, similar to the Moon, though cloud details are subtle in visible light. Ultraviolet imaging can reveal banded contrasts in the cloud tops, but to the eye the disk looks smooth and intensely bright.
Tech notes
The simulation runs in WebGL2 by default with ACES tone mapping and sRGB output. A simple multi-layer shader approximates Rayleigh/Mie-like scattering for a dense haze, with animated noise to suggest super-rotation. A back-faced sphere supplies a faint starfield for context. On compatible systems, enabling WebGPU can improve performance and precision. This is a real-time visualization for education and aesthetics—not a CFD model.