diff --git a/tools/etl/fetchDeepSky.ts b/tools/etl/fetchDeepSky.ts
index f2d4caa..4ba285b 100644
--- a/tools/etl/fetchDeepSky.ts
+++ b/tools/etl/fetchDeepSky.ts
@@ -126,7 +126,10 @@ export async function fetchDeepSky(): Promise<DeepSkyRecord[]> {
 
   // Brightest first, so a consumer taking a prefix gets the most prominent objects. Objects
   // with no measured magnitude sort last rather than being treated as infinitely bright.
-  records.sort((a, b) => (a.magnitude ?? Infinity) - (b.magnitude ?? Infinity) || a.id.localeCompare(b.id));
+  // The tie-break compares code points rather than localeCompare: locale collation depends on
+  // the ICU build of whichever Node runs the ETL, and a scheduled re-run must not reorder the
+  // file just because the runner's ICU disagrees with the machine that wrote it last.
+  records.sort((a, b) => (a.magnitude ?? Infinity) - (b.magnitude ?? Infinity) || (a.id < b.id ? -1 : a.id > b.id ? 1 : 0));
 
   ensureDataDir();
   writeFileSync(dataPath('deepsky.json'), JSON.stringify(records));
diff --git a/tools/etl/fetchExoplanets.ts b/tools/etl/fetchExoplanets.ts
index ade5d34..dac2b21 100644
--- a/tools/etl/fetchExoplanets.ts
+++ b/tools/etl/fetchExoplanets.ts
@@ -25,7 +25,11 @@ const TAP_COLUMNS = [
   'st_mass',
   'disc_year'
 ].join(',');
-const TAP_QUERY = `select+${TAP_COLUMNS}+from+ps+where+default_flag=1&format=csv`;
+// Ordered explicitly: without it the archive is free to return rows in any order, and a
+// scheduled re-run of the ETL would then rewrite exoplanets.json — and commit a diff — when
+// nothing was actually published. pl_name is unique among default_flag=1 rows, so the order
+// is total and the output is a pure function of the archive's content.
+const TAP_QUERY = `select+${TAP_COLUMNS}+from+ps+where+default_flag=1+order+by+pl_name&format=csv`;
 const TAP_URL = `${TAP_BASE_URL}?query=${TAP_QUERY}`;
 
 // A host star match must be within this many parsecs of the catalog position to be