diff --git a/docs/atlas/proposals/GJ421B.json b/docs/atlas/proposals/GJ421B.json
index 5bdc26a88..0eeef49b9 100644
--- a/docs/atlas/proposals/GJ421B.json
+++ b/docs/atlas/proposals/GJ421B.json
@@ -42,7 +42,7 @@
       "population": 800,
       "mass_class": "terrestrial",
       "surface_gravity": 0.84,
-      "orbital_period_days": 148.0,
+      "orbital_period_days": 115.0,
       "rotation_period_hours": 27.6,
       "atmosphere": "thin",
       "biome_summary": "cold_arid",
diff --git a/wiki/star-systems/GJ-421B/index.md b/wiki/star-systems/GJ-421B/index.md
index 1c4401377..c0a2ef52a 100644
--- a/wiki/star-systems/GJ-421B/index.md
+++ b/wiki/star-systems/GJ-421B/index.md
@@ -54,7 +54,7 @@ A community built around water management that survived its worst drought — an
 | Orbit | ID | Name | Type | Inhabited | Pop | Mass | Gravity | Year (d) | Day (h) | Atmo | Biome | Hydro | Economy | Settlement | Industrial |
 |---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
 | 1 | `GJ421Bb` | — | planet | no | — | terrestrial | 0.38g | 15 | 360.0 | none | barren | — | — | — | — |
-| 2 | `GJ421Bc` | Serpa | planet | yes | 800 | terrestrial | 0.84g | 148 | 27.6 | thin | cold_arid | liquid_water | agricultural | urban_concentrated | — |
+| 2 | `GJ421Bc` | Serpa | planet | yes | 800 | terrestrial | 0.84g | 115 | 27.6 | thin | cold_arid | liquid_water | agricultural | urban_concentrated | — |
 | 3 | `GJ421B-belt` | — | asteroid_belt | no | — | — | — | — | — | — | — | — | — | — | — |
 | 4 | `GJ421Bd` | — | planet | no | — | terrestrial | 0.50g | 460 | 27.2 | trace | frozen | — | — | — | — |
 | 5 | `GJ421Be` | — | planet | no | — | terrestrial | 0.40g | 1300 | 30.4 | trace | frozen | ice | — | — | — |
@@ -68,7 +68,6 @@ A community built around water management that survived its worst drought — an
 | ID | Name | Type | Orbits | Population | Economy | Governance | Docking | Gate | Districts |
 |---|---|---|---|---|---|---|---|---|---|
 | `GJ421B-oort-S1` | Pedra Seca Horizon | horizon | `GJ421B-oort` | 40 | transit | — | major | yes | 1 |
-
 ## Topology
 <!-- READ-ONLY — regenerated from star-map.json edges -->
 - **Hop Distance from Gateway:** 16