March 2026: Tidal Locking, True-Scale Moons, and the Milky Way Background

Three separate improvements landed in the solar system viewer this session, each addressing a physical accuracy or visual quality gap.

Tidal Locking — All 13 Moons

A tidally locked body always shows the same face to its parent planet — the Moon is the most familiar example. All 13 moons in the solar system viewer now implement this behaviour.

The implementation rotates each moon around its own Y axis at the same angular rate as its orbital revolution, and applies a lookAt correction each frame to compensate for Three.js's coordinate conventions. The result is that Io, Europa, Ganymede, Callisto, Titan, and the rest always present their correct hemisphere toward their parent.

True-Scale Moon Sizes

When the True Scale toggle is active, planet radii now scale to physical proportions. Moon radii previously defaulted to a fixed presentational size regardless of this toggle. They now follow the same scale factor — so Ganymede (larger than Mercury) appears noticeably bigger than the Moon when True Scale is enabled, and Deimos appears tiny compared to Phobos.

Collapsible Control Panels

The solar system control panel previously loaded fully expanded, occupying a significant portion of the viewport on first load. Panels now collapse by default with a smooth slide animation. This gives the 3D canvas more breathing room and reduces visual overwhelm on first visit.

Milky Way Background Sphere

The deep-space black background was replaced with a photorealistic Milky Way band. The implementation uses an equirectangular map projected onto a large sphere surrounding the solar system, oriented to match the actual galactic plane position relative to Earth's ecliptic.

Progressive loading strategy:

• A 2K texture loads immediately (fast, low bandwidth cost)
• On good network connections (effective type 4g), an 8K upgrade swaps in silently after the scene stabilises

The sphere is camera-tracked — it follows the camera position so the background never tiles or repeats as the camera moves through the solar system. A toggle-milky-way button lets users switch it off if they prefer the original black void.