Celestial Cup Home

Decoupled motion: rotate either Earth or the Constellations (never both simultaneously).

Select Active Moving Component

★ Move Constellations

🌍 Move Earth

Only the outer constellation cup will rotate (simulates the 24h diurnal sky while Earth remains stationary).

Time Speed & Rotation 60× (1 min/s)

Speed Multiplier:

Manual Angle Controls

Constellation Diurnal Angle: 0.0 hr (0°)

Earth Revolution (Day of Year): Day 80 (Mar)

Sidereal Time & Meridian Alignment

Active Moving Glass: Constellations (Sky)

Local Sidereal Time (LST): 00:00:00

Observer Zenith RA: 00h 00m

Earth Orbital Season: Vernal Spring

Map Image Files (.jpg / .png)

Inner Glass: Earth (EarthMap.jpg)[cite: 2] Outer Glass: Constellations (ConstellationMap.jpg)[cite: 2]

Display Settings

Constellation Opacity: 85% Cup Spacing Gap: 10 mm

• Independent Operation: Switching to "Move Constellations" completely freezes Earth to observe 24-hour diurnal rising/setting.
• Switching to "Move Earth" completely freezes the celestial sphere to observe the seasonal revolution of continents under the stars.
• Mouse Drag: Rotate the 3D perspective freely; scroll to zoom.