diff --git a/src/app/shared/rendering/body-orientation.ts b/src/app/shared/rendering/body-orientation.ts
index ccf270e..42dd4c8 100644
--- a/src/app/shared/rendering/body-orientation.ts
+++ b/src/app/shared/rendering/body-orientation.ts
@@ -19,7 +19,9 @@ const Z_AXIS = new THREE.Vector3(0, 0, 1);
  * Greenwich is in the middle of Earth's; on Mars's, Olympus Mons (226.2 E, which is -133.8) sits a
  * little over a third of the width left of centre; on the Moon's, Mare Crisium (59 E) is right of
  * centre and Mare Orientale (95 W) left of it; on Mercury's, the rayed crater Kuiper (31.5 W, 11 S)
- * is just left of centre and below the equator. A map labelled in west longitude, as most planets'
+ * is just left of centre and below the equator; on Venus's, Maxwell Montes (65.2 N, 3.3 E) is the
+ * brightest spot, high and just right of centre — Solar System Scope ships that map turned half
+ * round, south up, and it is kept turned back. A map labelled in west longitude, as most planets'
  * are, is still drawn with east to the right, as any map of a sphere seen from outside is; only its
  * numbers run the other way. So longitude 0 is +X and 90 E is -Z, and a quarter turn about X
  * carries that onto the IAU's body-fixed frame: pole +Z, prime meridian +X, 90 E +Y.
diff --git a/src/app/shared/rendering/texture-catalog.spec.ts b/src/app/shared/rendering/texture-catalog.spec.ts
index 465dde8..effbebf 100644
--- a/src/app/shared/rendering/texture-catalog.spec.ts
+++ b/src/app/shared/rendering/texture-catalog.spec.ts
@@ -1,3 +1,7 @@
+/// <reference types="node" />
+// Node, for the one test that reads a map's bytes from disk.
+import { createHash } from 'node:crypto';
+import { readFileSync } from 'node:fs';
 import * as THREE from 'three/webgpu';
 import { describe, expect, it } from 'vitest';
 
@@ -11,6 +15,16 @@ describe('bodyTexturePath', () => {
     }
   });
 
+  it('wraps Venus in the map turned north up, the one checked for Maxwell Montes', () => {
+    // As the Solar System Scope pack ships it, venus.jpg is the Magellan map turned half round:
+    // Maxwell Montes, 65.2 N 3.3 E in the IAU Gazetteer, was its brightest point at 63 S 9 W. The
+    // file turned back puts it at 63.7 N 8.3 E; see assets/textures/README.md. No decoder runs
+    // here, so the check is pinned to those bytes.
+    expect(bodyTexturePath('venus')).toBe('assets/textures/bodies/venus.jpg');
+    const bytes = readFileSync(`${process.cwd()}/src/assets/textures/bodies/venus.jpg`);
+    expect(createHash('sha256').update(bytes).digest('hex')).toBe('4528b8e9a3cf880d80e8a5321a3001e8792bc18f266c06f3456a6bd8475e021d');
+  });
+
   it('leaves the bodies with no map it could check to their derived surface', () => {
     for (const id of ['miranda', 'ariel', 'umbriel', 'titania', 'oberon', 'hyperion', 'eris']) {
       expect(bodyTexturePath(id)).toBeUndefined();
diff --git a/src/assets/textures/README.md b/src/assets/textures/README.md
index 61385a0..cdfeed7 100644
--- a/src/assets/textures/README.md
+++ b/src/assets/textures/README.md
@@ -12,6 +12,13 @@ prime meridian (W) then turns longitude 0 to where it belongs at any date.
 and the skybox come from the Solar System Scope texture pack, and `jupiter` from its 8k pack, via
 Wikimedia Commons. See each file's Commons page for the original credit line.
 
+`venus.jpg` is kept turned 180 degrees from the pack's file, which is the Magellan radar map with
+south up and east to the left: there Maxwell Montes (65.2 N, 3.3 E in the IAU Gazetteer), the
+brightest feature north or south of 50 degrees, sat at 63 S, 9 W, with Lakshmi Planum east of it
+instead of west. Turned back (PIL `ROTATE_180`, re-saved on the file's own quantisation tables, 0.03
+grey levels from the exact turn), its brightest point is at 63.7 N, 8.3 E, with Lakshmi to the west.
+`texture-catalog.spec.ts` pins the checked file's SHA-256.
+
 `saturn_ring.png` is a 1 280 by 78 px strip. Its x axis runs straight out from Saturn: read off its
 alpha, the C ring's inner edge (74 490 km) is at px 91, the B ring's inner and outer edges (92 000
 and 117 580 km) at 404.5 and 860, the A ring's outer edge (136 775 km) at 1 204 and the F ring
diff --git a/src/assets/textures/bodies/venus.jpg b/src/assets/textures/bodies/venus.jpg
index 48f8f15..b7d3933 100644
Binary files a/src/assets/textures/bodies/venus.jpg and b/src/assets/textures/bodies/venus.jpg differ