diff --git a/zk/Radio_wave_propagation.md b/zk/Radio_wave_propagation.md
index 932d296..aee0c44 100644
--- a/zk/Radio_wave_propagation.md
+++ b/zk/Radio_wave_propagation.md
@@ -44,6 +44,8 @@ splitting off particles.
 
 ## Relation to radio
 
+![](../img/ionosphere-scan-cropped.png)
+
 The ionosphere is used to propagate HF-band frequencies. When the waves hit the
 ionosphere, the charged particles interact with the wave and can bend it back
 towards the Earth. This facilitates long-distance radio communication.