Permanent day. Permanent night. Moving rock.

Trace the loop inside a locked world.

Predict the anchored upwelling, then select four checkpoints on the 3D cutaway in the order hot mantle travels.

Star-facing dayside

Dark nightside

Where does the main upwelling anchor?

Make a prediction before the circulation checkpoints unlock.

Choose an answer, then trace the illuminated checkpoints on the planet. Keyboard: keys 1 through 4.

Day-night forcing75% normalized

This is a conceptual lab control, not a measured value for a specific exoplanet. Stronger forcing accelerates the visible tracer without changing the anchored route.

Interpretation: the laboratory analogue supports a persistent global organization of mantle flow. It does not prove habitability, liquid water, an atmosphere, plate tectonics, or a magnetic field on any specific world.

Why the path stays geographically anchored.

Dayside rise

Permanent stellar heating fixes the hottest surface boundary near the substellar region, concentrating buoyant upwelling below it.

Upper transfer

Warm material spreads laterally through the upper mantle, redistributing geothermal energy rather than leaving each hemisphere isolated.

Nightside sink

Cooling beneath the antistellar region increases density, anchoring the principal downwelling on the dark side.

Deep return

Material closes the overturning loop through the deeper interior. Local plumes may vary while this large-scale organization persists.