Domain: Natural Science — Astrophysics & Astronomy
Target concept: The eight planets revolve around the Sun in the same direction, along nearly the same plane, and on nearly circular orbits, arranged from innermost to outermost as Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Video generation prompt: A dynamic diagram illustrating the orbital motion of the eight planets in the solar system around the Sun, with planetary names labeled from inside to outside on the same plane, and the direction of each planet's motion indicated.

Evaluation guide:
(i) Target concept: Coplanar, prograde, near-circular orbital motion of eight planets around a central star.
Minimum mechanism: All planetary trajectories must be closed, non-intersecting, radially ordered curves sharing a common center (Sun) and common normal vector (defining orbital plane); motion must be continuous, unidirectional, and synchronized in angular progression.
(ii)Storyline: Frame 1: Static setup: Sun centered, eight unlabeled planets placed on concentric circular orbits in correct radial order, all coplanar, no motion, no labels, no indicators. → Transition: Smooth onset of motion; all planets begin simultaneous counter-clockwise translation along orbital paths. → Mid-sequence: Continuous motion with labels fading in adjacent to each planet in radial order; directional indicators (curved arrows) appear and lock to each planet’s instantaneous tangent. → Sustained state: All eight planets maintain fixed radial order, strict coplanarity, identical motion direction, and stable label/indicator attachment. → Perspective constraint: Fixed overhead viewpoint (ecliptic north pole view); no camera movement, no parallax, no depth cueing that violates planarity.

Manual:
Experimental Procedure
1. Place Sun at center of frame.
2. Arrange eight distinct planetary bodies in concentric circular orbits around Sun, ordered Mercury → Venus → Earth → Mars → Jupiter → Saturn → Uranus → Neptune.
3. Animate all planets moving continuously in the same direction (counter-clockwise) along their orbits.
4. Label each planet with its name, positioned adjacent and radially outward, preserving inner-to-outer sequence.
5. Add directional indicators (e.g., small curved arrows or motion trails) aligned with orbital tangent at each planet.
Observation of Experimental Phenomena
- Eight labeled planets revolve synchronously in same direction around central Sun.
- All orbits lie in same flat plane — no planet appears above or below orbital disk.
- Labels remain fixed to respective planets and ordered radially from Sun outward.
- Directional indicators point consistently with orbital motion.
Summary of Experimental Principles
The eight planets revolve around the Sun in the same direction, along nearly the same plane, and on nearly circular orbits, arranged from innermost to outermost as Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.

Prompt Grounding rubric:
level_1: No Sun is depicted; no planetary bodies appear; the scene shows no orbital motion at all; no planet name labels appear anywhere in the frame; no directional indicators (arrows, trails, or arcs) are attached to any body.
level_2: A Sun-like central body is present, but fewer than eight distinct planetary bodies appear on screen; planet-name text labels are missing entirely or are attached to the wrong body (e.g., a label sits next to empty space or the Sun); no planet carries a directional indicator, or an indicator appears on a non-planet object (e.g., a background star).
level_3: A central Sun and exactly eight distinct planetary bodies are visible; text labels for Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune are each present and sit next to a planetary body; at least one planet carries a directional indicator (arrow, short trail, or curved arc) that is visibly attached to that planet's own path.
level_4: Everything at level 3 holds, and in addition each of the eight planets carries its own directional indicator that stays attached to that specific planet and points along that planet's own instantaneous direction of travel (regardless of whether that direction matches the other planets); every name label stays next to its assigned planet and remains readable for the full video, without swapping onto a different body.
level_5: Everything at level 4 holds, and in addition the eight planetary bodies are visually distinguishable from one another by size and/or color (a viewer could tell them apart without reading labels); all eight name labels remain fully legible, non-overlapping, and stay attached beside their own planet at every position it reaches; every directional indicator remains continuously attached to its planet with no detachment, no jump to a different body, and no moment where an indicator floats free of its planet.

Scientific and Causal Correctness rubric:
level_1: The eight planets do not all revolve in the same rotational sense (e.g., some circle clockwise while others circle counter-clockwise); at least one orbit is visibly elongated into an ellipse or crosses another planet's path; the visible order of planets from the Sun outward contradicts the true sequence (e.g., Jupiter drawn closer to the Sun than Venus); or the Sun is not positioned at the common center of the orbits.
level_2: At least two planets circle in the opposite rotational sense from the rest; at least three planets sit in the wrong position in the Mercury-to-Neptune distance order (e.g., Neptune drawn nearer the Sun than Earth); more than two orbital paths visibly cross each other; or the eight orbits are not confined to one shared flat plane (some planets are clearly offset above or below the others).
level_3: All eight planets circle the Sun in the same rotational sense as one another (uniformly clockwise or uniformly counter-clockwise); every planet sits in the correct Mercury-to-Neptune distance order from the Sun; every orbital path is a closed, roughly circular curve; and all eight orbits lie on one common flat plane with no planet visibly above or below the others.
level_4: Everything at level 3 holds, and in addition the shared rotational sense specifically matches the real solar system's prograde direction: counter-clockwise as seen from above the orbital plane's north side, not merely whichever single direction was chosen; the eight orbital paths stay smooth, closed, and non-intersecting at every frame; and no planet's position ever drifts out of the shared orbital plane.
level_5: Everything at level 4 holds, and in addition every orbital path stays close to a true circle and concentric with the Sun, with no inversions in the Mercury-to-Neptune order at any point in the video; every planet's center stays within the shared flat orbital disk with no visible tilt or vertical offset at any time; and each planet's directional indicator points along that planet's own true tangential direction of travel, matching the shared counter-clockwise sense.

Spatiotemporal Consistency rubric:
level_1: One or more planets abruptly jump from one position to another with no motion in between; the Sun's location jumps between frames; a name label blinks on and off or snaps to a new position without sliding there; an orbital path appears fully drawn in one frame with no prior tracing motion; or the scene's lighting or overall color shifts suddenly for no reason connected to the planets' motion.
level_2: At least three planets jump or skip ahead between frames instead of moving smoothly; at least two name labels separate from their planet and drift on their own path; an orbital path fades in or out partway through the video; or the Sun changes size or position more than once without a smooth in-between transition.
level_3: Every planet travels along its path with visibly continuous motion and no jumps; the Sun stays in the same place, size, and brightness for the whole video; every name label stays attached to its own planet; every directional indicator stays attached to its planet and keeps pointing along that planet's direction of travel; and no sudden, unexplained change in lighting or shading appears on any object.
level_4: Everything at level 3 holds, and in addition every planet's motion looks smooth and even-paced rather than jerky; the Sun shows no flicker, resizing, or repositioning at all; every label keeps a constant size, orientation, and legibility while staying attached to its planet; every directional indicator keeps a constant curvature and orientation relative to its planet's motion; and no planet, label, or indicator appears to shake, warp, or distort from one frame to the next.
level_5: Everything at level 4 holds, and in addition all eight planets' motion looks perfectly smooth and evenly paced with no visible stutter or sudden speed change anywhere in the video; the Sun shows absolutely no change in position, size, or brightness; no label or directional indicator ever drifts, rotates, resizes, or gets covered by another object; every orbital path looks like a smooth curve rather than a jagged, blocky line; and no planet, label, or path ever appears sheared, stretched, or inconsistently foreshortened between frames.