# Day 35 · A planet and its background

**Child start:** “Follow the named planet. Which background marks help you tell the change?”

**Useful finish:** A later-date relative-position caption. **Prerequisite:** Day 17 planet/background reference and Day 33 comparability. **Prepare:** Fixed named background markers J/K, planet token labelled “named planet; fictional schematic”, model date cards week 1/week 3/week 5. The token's identity is supplied; brightness is not identification. **Opportunities:** U01/I01/I04/I05/I06.

**Complete model:** Fictional schematic readings: week 1 planet above J; week 3 planet between J/K; week 5 planet below K. J/K remain fixed relative to each other in this model. A separately drawn horizon changes between pictures, so use the J/K relation for this question. No real astronomical coordinates, current planet location, equal movement speed or local sighting is supplied. Future week 7 position is not given.

**Run:**2 min child chooses position/background question;3 min compare week 1/week 3 only;7 min route;3 min ask what later record might help and why it stays unknown now. Extension: a tentative prediction stated before a separately supplied future card, if offered, must be retained before reveal; future actual visibility is not guaranteed.

**Route1 — Pin the background:** Child moves/directs the named token against J/K without moving them; makes an arrow labelled “change in this supplied sequence”, not speed. **Route2 — Diagnose an ambiguous caption:** Replace “it moved there” with object/reference/week words. Keep the changed horizon note but do not use it as a fixed reference. **Route3 — Make a record request:** Compose a short request for another later-date J/K record; it is a classroom draft, not a message sent to a real observatory.

**Notice/next:** Names the actual relation/ref/time span. If all motion is called same-day star grouping, put the two distinct question headings beside each other. B-later becomes eligible after this plus the later ordinary clarification on Day 36 if required. Home H05; C09–10; X05.

## Ready doors

[Ordinary example C09](../ordinary/C09.html) · [Another example C10](../ordinary/C10.html) · [Home H05](../home/H05.html) · [Project X05](../extras/X05.html) · [Read-aloud](../readaloud/day-35.html) · [Paper and picture aids](../aids/START.html) · [Sky Desk](../interactive/index.html)

[Participation and preparation](START.html) · [Mapping](CURRICULUM.html)
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