RSS Tracking

I recently told my wife about RSS readers, how they gathered news articles and anything else that is affiliated. At first she was quite impressed then she asked "So I can track a certain story and it will find it all the articles for me..?" I had to admit that the reader I have does not do that - and after a quick search I don't think that I can find one that does.

So dear reader how about this: each page on a news website adds keywords to their stories, let take an example Europa and the discovery of water and say for example we are interested in this subject.

What do we do? We open our RSS Reader and enter the search terms that we wish to keep track of in this case Europa & Water & Jupiter and we give our search a name "Water on Europa". Our RSS Reader then looks through all the content websites that we have subscribed to and pulls back all the pages that have the key words Europa & Water & Jupiter and places the links in our "Water on Europa" feed. The nearest I have found is a google news search

Simple eh..?