What the two rings compare
The outer blue ring holds the ten planets at the recorded birth minute. The inner red ring holds the same bodies at the later time when the moving Moon reaches the tropical zodiac degree directly opposite its natal degree. Zodiac symbols and the position table make each ring readable without assuming that nearby glyphs have the same longitude.
The event chart is sampled at the nearest UTC minute after the exact Moon crossing is estimated. Its houses belong to the chosen event place; natal houses belong to the birth place. Changing only the event place preserves the crossing instant and planetary degrees while shifting the local horizon and house placements.
The two-ring reading guide explains the time calculation, place choices, and how this chart differs from a lunar return. For a larger view of only the later sky, use the standalone opposition chart.