C09 · A planet museum label

Prepare background marks E/F and a named fictional planet token. Archive month-label a puts it beside E, label b halfway toward F, label c beside F; E/F relation retained in this schematic. Ask for a caption useful to a museum visitor. Worked reasoning: the supplied relation changed over later dates against E/F; it is not a current position, speed or identity-from-brightness result. Finish with object/reference/time/source. Next help: compare a nearby horizon border that changed, then explain why it is a different reference question. Sources and reuse · Choose another route