Im writing a short sci-fi novel and during the research fase I stumbled upon the deep learning and natural language processing concepts. In this question they say that the grammar induction is a supervised learning mode. So I was wondering:Lets say that theres a way-more-than-human intelligent alien probe orbiting our planet. It can receive, decode and analyze all the broadcasting signals leaving the Earth. For all we know at this moment, how could it learn the basics of a language with nothing else but our broadcasting signals, so without the help from a supervisor? How would an artificial intelligence human engineer (theoretically?) face the problem?Sorry for the bad english - probably the probe is better than me :D - and for not posting on Worldbuilding, but Im interested on the more technical side of the issue. 
Unsupervised alien natural language learning
natural language;unsupervised learning