diff --git a/game/CMakeLists.txt b/game/CMakeLists.txt
index 35f1f0a..8d2e44f 100644
--- a/game/CMakeLists.txt
+++ b/game/CMakeLists.txt
@@ -15,6 +15,8 @@ set(GAME_SRC
     util.cpp
     game.cpp
     state/object.cpp
+    state/explosion.cpp
+    state/trace.cpp
     state/state.cpp
     state/player.cpp
     state/planet.cpp
diff --git a/game/state/explosion.hpp b/game/state/explosion.hpp
index 2cf92ef..66c234f 100644
--- a/game/state/explosion.hpp
+++ b/game/state/explosion.hpp
@@ -1,17 +1,32 @@
 #pragma once
 
-#if 0
-class Explosion {
-public:
-    enum class Kind {
-        Normal,
-        MissileWithShip
+#include <glm/vec2.hpp>
+
+namespace game {
+    /**
+     * Explosion: just an effect which looks good.
+     */
+    class Explosion {
+    public:
+        enum class Kind {
+            MissileExplodesInSpace, // missile explode in free space
+            MissileAgainstPlanet,   // explosion of missile when it hits a planet
+            MissileAgainstShip      // bigger explosion: missile hits a ship which explodes with it
+        };
+
+        Explosion(const glm::vec2 &pos, Kind kind, float maxAge=1.0)
+            : position(pos), kind(kind), age(0.0), maxAge(maxAge)
+        {
+        }
+
+        const Kind      kind;     // kind of the explosion
+        const glm::vec2 position; // position where it starts
+        float           age;      // age (in seconsd) of the explosion
+
+        // age (in seconds) when the explosion is not visible
+        // anymore and will disappear afterwards
+        const float     maxAge;
     };
+}
 
-    glm::vec2 position;
-
-    Explosion(Kind kind);
-
-public:
-};
 #endif
diff --git a/game/state/trace.cpp b/game/state/trace.cpp
new file mode 100644
index 0000000..e69de29
diff --git a/game/state/trace.hpp b/game/state/trace.hpp
new file mode 100644
index 0000000..5c7f050
--- /dev/null
+++ b/game/state/trace.hpp
@@ -0,0 +1,24 @@
+#pragma once
+
+#include <glm/vec2.hpp>
+
+namespace game {
+    /*
+     * Trace of a missile through the space.
+     * Useful for rendering sth. like a smoke trail to follow the rocket.
+     */
+    class Trace {
+        public:
+            Trace(const glm::vec2 &startPoint)
+            {
+                points.push_back(startPoint);
+            }
+
+            void addPoint(const glm::vec2 &p)
+            {
+                points.push_back(p);
+            }
+
+            std::vector<glm::vec2> points;
+    };
+}