Why does my Sky tv go off when it's raining hard?

Submitted by Pops on Tuesday 29th Dec 2009

Dr Flame says...

This links in quite nicely with a previous question about how microwave ovens work...  How?  Well... Your satellite dish is receiving signals which lie in the "microwave band" of the electromagnetic spectrum.  There are differences between satellite signals and ovens though.  The main difference (aside from the power and concentration of the microwaves) is that the sky signals are transmitted at a frequency of about 10 GHz (meaning the signals oscillate 10 billion times a second!) whereas the frequency a microwave oven works at is around 2.5GHz - either way though, water molecules love them!  When it's raining only a little, most of the signals from the satellite make it through to the sensor on the dish, but when its raining heavily, the water acts like a barrier so blocking the signal.  

This question has been tagged Physics.