I would like to build an antenna for receiving NOAA weather satellites. They're receivable at around 137.5 Mhz. I'm a total new to amateur radio stuff. I know that it's not legal to communicate as private person on several frequency areas- so I would like to know if it's legal to "listen-only" to those satellites on this frequency. 

I'm here because I haven't found any sources proofing that it's legal or not.

If it matters, I live in Germany.