Domain: Natural Science — Astrophysics & Astronomy
Target concept: Total Lunar Eclipse

Video generation prompt: Show the complete process of the Moon's color and phase changes as observed from Earth during a total lunar eclipse.

Evaluation guide:
(i) Target concept: Earth-centered lunar eclipse observable from Earth surface, where Moon passes through Earth's shadow cone and is illuminated solely by refracted sunlight filtered through Earth's atmosphere.
Minimum mechanism: Requires (a) Earth positioned directly between Sun and Moon, (b) Earth's atmosphere acting as a red-light filter and lens, (c) observer located on Earth's night side with unobstructed view of Moon, (d) absence of major atmospheric opacity events (e.g., volcanic aerosols) that would suppress red light.
(ii)Storyline: [Phase 1: Normal Full Moon] Moon fully illuminated, silvery-gray, high contrast against stars. [Phase 2: Penumbral onset] East limb subtly dims; no color change; shadow boundary imperceptibly soft. [Phase 3: Partial umbral] Sharp, convex dark edge advances westward; exposed portion remains normal gray; shadow curvature matches Earth's limb. [Phase 4: Totality] Entire Moon inside umbra; color shifts continuously to deep copper-red; no direct sunlight reaches any part of Moon. [Phase 5: Umbral exit] Shadow boundary continues sweeping in the same westward direction it took during entry (not reversed); sunlit gray returns first along the eastern side of the disk while the shrinking dark area retreats toward the western limb, where the last sliver of umbral shadow finally clears. [Phase 6: Penumbral fade] Final dimming lifts uniformly; Moon returns to full silvery-gray. All transitions occur from fixed geocentric viewpoint with stable horizon/stars; no camera repositioning or zoom.

Manual:
Experimental Procedure
1. Begin with full Moon visible against starry night sky.
2. Gradually introduce faint, diffuse penumbral shadow on Moon's eastern limb.
3. Progress to sharp, curved umbral shadow advancing westward across Moon.
4. Complete umbral immersion: entire Moon inside dark umbra, glowing deep copper-red.
5. Umbral shadow continues its westward sweep until it clears the disk from the western limb, then penumbral dimming fades uniformly.
Observation of Experimental Phenomena
- Penumbral phase: subtle, uniform dimming without color shift.
- Partial phase: sharp, convex shadow edge moving across Moon; unaffected portion remains silvery-gray.
- Total phase: entire Moon within umbra, uniformly reddish-copper, no brightness gradient across disk.
- Exit phases repeat the same sequence of visual states in reverse order (totality, then partial, then penumbral), while the shadow's edge keeps moving in the same westward direction throughout rather than reversing.
Summary of Experimental Principles
Earth blocks direct sunlight; only refracted long-wavelength (red/orange) light from Earth's sunrises/sunsets illuminates Moon during totality. Umbra is cone-shaped and circular when viewed face-on; penumbra surrounds it with graded attenuation.

Prompt Grounding rubric:
level_1: No Moon disk is shown, no dark Earth-shadow region ever appears on it, and the video does not present a phase-by-phase eclipse sequence: e.g., it shows a diagram from the Sun's point of view, an extreme close-up of lunar craters, or an unrelated night-sky scene instead of an Earth-observed lunar eclipse.
level_2: The Moon disk appears but stays a single flat gray/silver color and never changes across the video; the Earth-shadow is missing, mislabeled (e.g., presented as a comet's tail or a solar eclipse), or wrongly shaped (e.g., a straight-edged bar instead of a curved shadow); or the Moon is shown either never touched by any shadow or fully swallowed by solid black with no partial-coverage stage shown at all.
level_3: The Moon and a circular, centrally-aligned dark shadow region are both clearly visible; the sequence shows at least two distinct coverage stages (a partial bite taken out of the disk by a curved shadow edge, and later the entire disk sitting inside the shadow), even if no color change appears yet; the shadow's curvature and position relative to the Moon look geometrically plausible rather than arbitrary.
level_4: The sequence visibly passes through four coverage stages in the correct order: faint, edgeless dimming beginning at one limb; a sharp curved shadow edge advancing across the disk; the whole disk sitting inside the shadow; and the curved edge later retreating as the disk re-emerges. The Moon stays centered in the frame throughout, and the shadow's outline remains a smooth circular arc concentric with the Moon at every stage.
level_5: Everything in Level 4 holds, AND the Moon's own brightness/hue visibly changes as a continuous progression while the disk sits fully inside the shadow (subdued near the moment of full immersion, changing further toward mid-totality, and easing back before the disk begins to re-emerge), with no instantaneous jump to an unrelated color patch (e.g., a flash of blue, green, or pure white) and no moment where the shadow's edge stops reading as a smooth curved arc.

Scientific and Causal Correctness rubric:
level_1: The color sequence contradicts real eclipse physics (for instance the Moon flashes bright white or turns blue while fully inside the shadow, or the shadow region never reads darker than the surrounding night sky), so nothing on screen suggests Earth's atmosphere is bending sunlight onto the Moon.
level_2: While the disk sits fully inside the shadow it goes solid black or featureless rather than glowing a visible color; the shadow shows no soft-edged outer zone separate from a darker inner zone (penumbra and umbra look identical); any reddish tint present is a flat, uniform overlay applied to the whole scene rather than something tied to the shadow's own progress across the disk.
level_3: The shadow clearly shows both a faint, softer outer zone and a darker inner zone; the Moon shows two distinguishable color states (ordinary gray/silver before the darker inner zone reaches it, and a reddish tone once the disk sits fully within that darker inner zone), and the reddish tone disappears again as soon as the disk begins leaving the darker zone.
level_4: Everything in Level 3 holds, AND the reddish tone is time-limited to the stretch when the disk is fully inside the darker inner zone: no reddish cast appears while the disk is only partly covered or only touched by the faint outer zone; the faint-zone dimming stays visibly weaker and closer to neutral gray than the inner-zone reddening.
level_5: Everything in Level 4 holds, AND the reddish tone stays confined to whichever part of the disk currently sits inside the darker inner zone rather than washing evenly over the whole Moon regardless of shadow position; the tone builds up gradually from the inner zone's edge toward the disk's middle rather than switching on all at once as a flat mid-eclipse color; brightness across the disk never inverts so the center reads lighter than the rim during the darkest stage.

Spatiotemporal Consistency rubric:
level_1: The Moon's position jumps between frames instead of moving along a continuous path; the shadow region flickers, vanishes, or changes shape in a single instant; there are hard cuts or dropped frames that break the sequence; or the surrounding night sky's brightness changes erratically from one frame to the next with no gradual buildup.
level_2: The Moon's advance into the shadow looks stuttery or uneven: visibly speeding up and stalling rather than gliding; the shadow's edge moves along a bumpy or angular path instead of a smooth arc; background stars or the horizon jump in position or number between frames; or the sky's ambient brightness changes in sudden steps rather than easing gradually.
level_3: The Moon moves along one continuous, smooth arc across the frame; the shadow's edge advances and later retreats with steady curvature and stays aligned with the Moon's outline; the background star field or horizon stays consistent in layout and density; no structural breaks occur (the Moon never splits, the shadow's edge never tears, the limb never distorts).
level_4: Everything in Level 3 holds, AND the shadow edge's advance across the disk keeps a steady, unhurried pace rather than lurching forward in bursts; the Moon's apparent size and outline stay constant throughout (no stretching, scaling, or flattening); no sudden shift in overall scene brightness or contrast happens between one frame and the next.
level_5: Everything in Level 4 holds, AND the pacing of the whole sequence stays smooth and unhurried from first dimming to final brightening: the penumbral phase visibly lasts longer than the partial phase, and the partial phase in turn lasts longer than totality; no phase collapses into a near-instant flash while other phases drag on, and no stage's shadow motion suddenly speeds up or slows down for no visible reason; the background stars hold a fixed positional relationship to the Moon's path with no drifting or sliding relative to one another.