diff --git a/src/asteroids.rs b/src/asteroids.rs
new file mode 100644
index 0000000..ca7e363
--- /dev/null
+++ b/src/asteroids.rs
@@ -0,0 +1,51 @@
+/// This is the module containing all the rock-related things
+/// not... not the whole game.
+use bevy::prelude::*;
+
+use crate::{GameAssets, Position, Rotation, Velocity};
+
+#[derive(Component, Deref, DerefMut)]
+struct Asteroid(AsteroidSize);
+
+enum AsteroidSize {
+    SMALL,
+    MEDIUM,
+    LARGE,
+}
+
+#[derive(Resource)]
+struct AsteroidSpawner {
+    timer: Timer,
+    // TODO: Configurables?
+    // - interval
+    // - density
+    // - size distribution
+}
+
+/// Update the asteroid spawn timer and spawn any asteroids
+/// that are due this frame.
+fn tick_asteroid_manager(
+    mut commands: Commands,
+    mut spawner: ResMut<AsteroidSpawner>,
+    game_assets: Res<GameAssets>,
+    time: Res<Time>,
+) {
+    spawner.timer.tick(time.delta());
+    if spawner.timer.just_finished() {
+        commands.spawn((
+            Asteroid(AsteroidSize::SMALL),
+            Position(Vec2::new(40.0, 40.0)),
+            Velocity(Vec2::new(10.0, 0.0)),
+            Rotation(0.0),
+            Mesh2d(game_assets.asteroid_small().0),
+            MeshMaterial2d(game_assets.asteroid_small().1),
+        ));
+    }
+}
+
+/// Utility function to spawn a single asteroid of a given type
+/// TODO: convert to an event listener monitoring for "spawn asteroid" events
+/// from the `fn tick_asteroid_manager(...)` system.
+fn spawn_asteroid(mut commands: Commands) {
+    todo!();
+}
diff --git a/src/lib.rs b/src/lib.rs
index 20137e6..8ee7bf3 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,3 +1,4 @@
+mod asteroids;
 pub mod config;
 mod preparation_widget;
 mod title_screen;
@@ -73,24 +74,6 @@ struct Rotation(f32);
 #[derive(Component)]
 struct Ship;
 
-#[derive(Component, Deref, DerefMut)]
-struct Asteroid(AsteroidSize);
-
-enum AsteroidSize {
-    SMALL,
-    MEDIUM,
-    LARGE,
-}
-
-#[derive(Resource)]
-struct AsteroidSpawner {
-    timer: Timer,
-    // TODO: Configurables?
-    // - interval
-    // - density
-    // - size distribution
-}
-
 /// Marker for any entity that should wrap on screen edges
 #[derive(Component)]
 struct Wrapping;
@@ -212,34 +195,6 @@ fn spawn_player(mut commands: Commands, game_assets: Res<GameAssets>) {
         ));
 }
 
-/// Update the asteroid spawn timer and spawn any asteroids
-/// that are due this frame.
-fn tick_asteroid_manager(
-    mut commands: Commands,
-    mut spawner: ResMut<AsteroidSpawner>,
-    game_assets: Res<GameAssets>,
-    time: Res<Time>,
-) {
-    spawner.timer.tick(time.delta());
-    if spawner.timer.just_finished() {
-        commands.spawn((
-            Asteroid(AsteroidSize::SMALL),
-            Position(Vec2::new(40.0, 40.0)),
-            Velocity(Vec2::new(10.0, 0.0)),
-            Rotation(0.0),
-            Mesh2d(game_assets.asteroid_small().0),
-            MeshMaterial2d(game_assets.asteroid_small().1),
-        ));
-    }
-}
-
-/// Utility function to spawn a single asteroid of a given type
-/// TODO: convert to an event listener monitoring for "spawn asteroid" events
-/// from the `fn tick_asteroid_manager(...)` system.
-fn spawn_asteroid(mut commands: Commands) {
-    todo!();
-}
-
 /*
  Checks if "W" is pressed and increases velocity accordingly.
 */