diff --git a/changelog.d/1243-starfield-sky.md b/changelog.d/1243-starfield-sky.md
index 91096628f..7d4557672 100644
--- a/changelog.d/1243-starfield-sky.md
+++ b/changelog.d/1243-starfield-sky.md
@@ -1,5 +1,5 @@
 - Replace the blocky JPEG sky around the globe with the 9,096 stars of the
-  Yale Bright Star Catalogue, drawn as sharp points where each star really is
-  at the scene clock, over a soft Milky Way built from ESO/S. Brunier's
-  panorama (CC BY 4.0). The Sun and Moon stay; the new assets weigh 482 KB
-  (gekh, #1243).
+  Yale Bright Star Catalogue, drawn as sharp points at their catalogue
+  positions for the scene clock, over a soft Milky Way built from ESO/S.
+  Brunier's panorama (CC BY 4.0). The Sun and Moon stay, the anime style fades
+  the Milky Way out, and the new assets weigh 319 kB (gekh, #1243).
diff --git a/scripts/build-milky-way.mjs b/scripts/build-milky-way.mjs
index 19b2ea1e9..5e5d3d253 100644
--- a/scripts/build-milky-way.mjs
+++ b/scripts/build-milky-way.mjs
@@ -29,9 +29,9 @@
  *      axes as the cube axes — +X to the March equinox, +Z to the north
  *      celestial pole — rotating each direction into galactic coordinates
  *      with the IAU J2000 matrix.
- *   6. Map the darkest 25 % of the sky to black and the brightest 0.01 % to
- *      white, encode with gamma 1/2.2 and ±0.5 LSB dither against banding;
- *      WebP.
+ *   6. Map the median sky to black, easing in with a soft knee, and the
+ *      brightest 0.01 % to white (on luminance, keeping each pixel's hue),
+ *      encode with gamma 1/2.2 and ±0.5 LSB dither against banding; WebP.
  *
  * Usage:
  *   node scripts/build-milky-way.mjs <eso0932a.tif>
@@ -46,10 +46,12 @@ export const BLUR_DEG = 0.4;
 const WORK_WIDTH = 4096;
 const OPEN_RADIUS = 3;
 const WEBP_QUALITY = 96;
-// The darkest quarter of the sky is the black level: away from the galactic
-// plane the panorama carries a mottled glow of unresolved stars that would
-// read as grey fog around the globe.
-const BLACK_PERCENTILE = 0.25;
+// The median sky is the black level: away from the galactic plane the
+// panorama carries a mottled glow of unresolved stars and dust that reads as
+// grey blotches around the globe. A hard cut there draws edges of its own, so
+// the level eases in over SOFT_KNEE (a fraction of the black-to-white range).
+const BLACK_PERCENTILE = 0.5;
+const SOFT_KNEE = 0.03;
 const WHITE_PERCENTILE = 0.9999;
 const OUT_DIR = path.join(
   path.dirname(fileURLToPath(import.meta.url)),
@@ -289,6 +291,15 @@ function dither(index, channel) {
   return (h >>> 0) / 4294967296 - 0.5;
 }
 
+/**
+ * Black level with a soft knee: 0 at and below the level, then a quadratic
+ * ease that joins the straight line, so faint sky fades out instead of
+ * ending in a contour.
+ */
+export function softBlack(x, knee = SOFT_KNEE) {
+  return x <= 0 ? 0 : (x * x) / (x + knee);
+}
+
 /** Value at `fraction` of the sorted luminance. */
 function luminancePercentile(planes, fraction) {
   const [r, g, b] = planes;
@@ -346,12 +357,14 @@ async function main() {
         );
         const [u, v] = directionToPlateCarree(...icrfToGalactic(direction));
         const index = j * FACE_SIZE + i;
+        const rgb = [0, 1, 2].map((c) =>
+          samplePlane(planes[c], width, height, u, v),
+        );
+        const luminance = (rgb[0] + rgb[1] + rgb[2]) / 3;
+        const level = softBlack((luminance - black) / (white - black));
         for (let c = 0; c < 3; c++) {
-          const linear = Math.max(
-            (samplePlane(planes[c], width, height, u, v) - black) /
-              (white - black),
-            0,
-          );
+          // Scale every channel by the luminance curve to keep the hue.
+          const linear = luminance > 0 ? (rgb[c] / luminance) * level : 0;
           const encoded = Math.min(linear, 1) ** (1 / 2.2) * 255;
           pixels[index * 3 + c] = Math.min(
             255,
diff --git a/src/data/local_data/sky/README.md b/src/data/local_data/sky/README.md
index e224e7bb0..175542da5 100644
--- a/src/data/local_data/sky/README.md
+++ b/src/data/local_data/sky/README.md
@@ -8,7 +8,7 @@ whole-globe view and show compression blocks.
 | File | Content | Size |
 | ---- | ------- | ---- |
 | `bright_stars.json` | 9,096 stars: J2000 RA/Dec, V magnitude, B−V | 235 KB |
-| `milkyway_{px,nx,py,ny,pz,nz}.webp` | Milky Way glow, six 1024² cube faces, no stars | 247 KB |
+| `milkyway_{px,nx,py,ny,pz,nz}.webp` | Milky Way glow, six 1024² cube faces, no stars | 85 KB |
 
 ## Stars — Yale Bright Star Catalogue
 
@@ -45,7 +45,8 @@ Centre.
 4096×2048, stars removed with a 7×7 morphological opening, two planets
 (Jupiter, by position) painted over with the median of the surrounding sky,
 blurred (σ = 0.4°), reprojected from galactic coordinates to ICRF cube faces,
-black level set at the darkest 25 % of the sky, gamma-encoded and saved as
+black level set at the median sky with a soft knee (the faint glow away
+from the galactic plane fades to black), gamma-encoded and saved as
 WebP. Build:
 `node scripts/build-milky-way.mjs <eso0932a.tif>`.
 
diff --git a/src/data/local_data/sky/milkyway_nx.webp b/src/data/local_data/sky/milkyway_nx.webp
index d74db8e52..9c75115c5 100644
Binary files a/src/data/local_data/sky/milkyway_nx.webp and b/src/data/local_data/sky/milkyway_nx.webp differ
diff --git a/src/data/local_data/sky/milkyway_ny.webp b/src/data/local_data/sky/milkyway_ny.webp
index bec3fb4d3..a85f3d47e 100644
Binary files a/src/data/local_data/sky/milkyway_ny.webp and b/src/data/local_data/sky/milkyway_ny.webp differ
diff --git a/src/data/local_data/sky/milkyway_nz.webp b/src/data/local_data/sky/milkyway_nz.webp
index de654a4f2..154e0454f 100644
Binary files a/src/data/local_data/sky/milkyway_nz.webp and b/src/data/local_data/sky/milkyway_nz.webp differ
diff --git a/src/data/local_data/sky/milkyway_px.webp b/src/data/local_data/sky/milkyway_px.webp
index 3c0aead6f..2bbb49174 100644
Binary files a/src/data/local_data/sky/milkyway_px.webp and b/src/data/local_data/sky/milkyway_px.webp differ
diff --git a/src/data/local_data/sky/milkyway_py.webp b/src/data/local_data/sky/milkyway_py.webp
index 444093007..779353c64 100644
Binary files a/src/data/local_data/sky/milkyway_py.webp and b/src/data/local_data/sky/milkyway_py.webp differ
diff --git a/src/data/local_data/sky/milkyway_pz.webp b/src/data/local_data/sky/milkyway_pz.webp
index 8fecc2d52..50f0793a6 100644
Binary files a/src/data/local_data/sky/milkyway_pz.webp and b/src/data/local_data/sky/milkyway_pz.webp differ
diff --git a/src/tooling/skyAssets.test.mjs b/src/tooling/skyAssets.test.mjs
index 697c8f13e..5c666e87d 100644
--- a/src/tooling/skyAssets.test.mjs
+++ b/src/tooling/skyAssets.test.mjs
@@ -9,6 +9,7 @@ import {
   cubeFaceDirection,
   directionToPlateCarree,
   icrfToGalactic,
+  softBlack,
 } from '../../scripts/build-milky-way.mjs';
 import { raDecToUnitVector } from '../sky/stars.js';
 
@@ -105,3 +106,18 @@ test('the galactic rotation puts the Galactic Centre and pole where the IAU does
   close(u, 0.5 + (360 - 280.47) / 360, 2e-3);
   close(v, 0.5 + 32.89 / 180, 2e-3);
 });
+
+test('the black level eases in instead of cutting the faint sky into contours', () => {
+  assert.equal(softBlack(-0.2), 0);
+  assert.equal(softBlack(0), 0);
+  // Continuous, rising, with no step at the black level.
+  let previous = 0;
+  for (let x = 0.001; x <= 1; x += 0.001) {
+    const y = softBlack(x);
+    assert.ok(y > previous && y - previous < 0.0011, `step at ${x.toFixed(3)}`);
+    previous = y;
+  }
+  // Starts flat, then joins the straight line just below it.
+  assert.ok(softBlack(0.003) < 0.0003);
+  close(softBlack(1), 1 - 0.03, 1e-3);
+});