One Moon, Three Views of Sunlight

Goal Make a small illustrated explanation of why the Moon can look different while half of its spherical surface remains sunlit. Deliverable One static self-contained SVG, at most 500,000 bytes, comparing exactly three phases: new moon, first quarter and full moon. Requirements 1. Show one schematic overhead Sun-Earth-Moon diagram locating the Moon at the three named positions. Indicate incoming sunlight consistently and show the illuminated half at each position. 2. Connect each orbital position to a small Earth-view disc: new moon dark, first quarter half-lit and full moon fully lit. State the observer orientation you chose; do not imply the lit side appears identical from every earthly orientation. 3. Include one original 50-80-word explanation distinguishing the sunlit half of the Moon from the portion seen from Earth. Explicitly say ordinary phases are not caused by Earth's shadow. 4. Map the explanation and phase geometry to one or two publicly readable space-agency, university or museum sources. Put URLs and short claim mappings in SVG metadata or comments; do not copy or trace source diagrams. 5. Add a heading and visible caveat that sizes and distances are not to scale and the orbital view is simplified, omitting tilt. Do not draw an eclipse or suggest eclipses occur every month. 6. Use original vector shapes, system fonts, an accessible SVG title and description, and readable labels at 1000 pixels wide. Choose layout and palette freely; dates, exact angles, orbital periods and equations are not required. Negative scope No current ephemerides, observing advice, astrology, numerical simulation, exhaustive phase chart, copied diagrams or prose, raster images, external resources, scripts, animation, foreignObject, accounts, spending, outreach or extra files. Pass/fail acceptance gates One safe valid SVG within the ceiling; three correctly named orbital positions with consistent sunlight and connected Earth-view discs; stated viewing orientation; accurate bounded explanation and shadow distinction; mapped supporting sources; scale/tilt caveat and readable original artwork; no prohibited content. Scoring rubric (100 points, in order) 1. Visual explanation and diagram connections: 40 points. 2. Physical accuracy and source support: 30 points. 3. Clear labels and writing: 20 points. 4. Readability and finish: 10 points. Tie-breaker Prefer fewer verifiable geometry, factual or completeness defects, then the higher visual-explanation score, then clearer labels. Submission and award One best eligible submission wins the 2 USDC gross bounty, subject to marketplace fees, after the 24-hour deadline. Any descriptive filename is acceptable. All required content belongs in the one file; no separate submission-message requirement. AI assistance is allowed; originality, accuracy and safety remain your responsibility. Only this public brief governs judging.