How do I save my parents' marriage?

My parents have been together for twenty something years, and as far as I know they always loved each other. They have had their differences but in the long run they have always worked them out,and moved ahead. They have gone through so much together both good and bad, they started a new life in another country helping each other and its through the efforts of them both that we all are where we are today. Lately my parents have been fighting a lot. Financial troubles have taken its toll on them and their relationship, but the things they fight about are the most ridiculous things its actually quite pathetic. My parents are two very different people, they are both hard working people tho. My mother feels like shes the Queen of England, when shes angry no one can talk to her, when shes depressed or sad everyone has to cater to her and make her feel better, when shes happy we all have to smile because God forbid were not in the same good mood she is in. She controls my father a lot, he actually has to ask for permission to watch a game of soccer on the T.V.!!! Why? Because she does not like watching or hearing that, when she herself rarely watches T.V. My mother is very impatient and fights for what she wants and she has a very special skill of being able to hurt other people with two words. My father on the other hand is easy-going, and patient. He likes to do things at their pace. He sits in front of the T.V. everyday when he comes home, or in front of his computer. We live in a place where the idea of social outings is going to the bar and getting drunk. We moved here from NY and my parents used to go out like every other weekend, and here they are just concentrated on working, and school and that's pretty much it. My parents have recently had a " disagreement" because my mom lost her work on the computer and she couldn't find it and my dad tried helping her and he apparently gave her attitude and yadda yadda. Now my mom isn't talking to him, he's sleeping out on the couch. My mom actually LOCKS the door to her room, and me and my sister have to knock to go talk to her, and she barely looks at my dad. She has actually has stated that she wants to leave and all that stuff. Now me and my sister are old enough to take care of ourselves so that's not a problem. My dad is sick of my mom's "prima-donna" actions saying that he loves her a lot but if he has to leave her to live in peace he will do so, and my mom has no problem leaving too. I have decided that if they do separate that I will live with neither one of them, and figure something out for me and my sister. But until then it would really be a ***** move if they did separate. I think its ridiculous how all the preaching that they did about families sticking together and being the basis of whatever crap is now put in the back seat! I don' t want them to separate, I know I'm old enough to handle it but at the same time I'm wondering if I can actually handle it. There has to be someway to prevent this from happening!