diff --git a/circleshape.py b/circleshape.py
index eb08882..5658953 100644
--- a/circleshape.py
+++ b/circleshape.py
@@ -13,6 +13,13 @@ class CircleShape(pygame.sprite.Sprite):
         self.velocity = pygame.Vector2(0, 0)
         self.radius = radius
 
+    def is_colided(self,other_circle):
+        distance = self.position.distance_to(other_circle.position)
+        if other_circle.radius + self.radius <= distance:
+            return True
+        else:
+            return False
+
     def draw(self, screen):
         # sub-classes must override
         pass
diff --git a/main.py b/main.py
index f65a729..b6711f5 100644
--- a/main.py
+++ b/main.py
@@ -45,9 +45,12 @@ def main():
         
         for drawable in drawables:
             drawable.draw(screen)
-        
         for updatable in updatables:
             updatable.update(dt)
+        for asteroid in asteroids:
+            if asteroid.is_colided(p1):
+                print("Game Over!")
+                return
         
         pygame.display.flip()
         tick = clock.tick(60)