Advice/Suggestions? 9 Days in NW of Argentina from BsAs

Hi! I'm a student in Buenos Aires, and I have about nine days off from class to travel in May. I want to make my way up through the northwest by bus and then fly back.

Any suggestions on a good route? What do I need to see? Is it possible to see everything without renting/driving a car?

Any kind tips or advice would be greatly appreciated.

There is much to see in the northwest, but travelling there takes time. I had a month, and managed only to see a few spots. So no, it's not possible to see everything, whatever thay may be. Wouldn't be possible by car either.

You shouldn't miss out on Salta. Jujuy is also very nice, as is Catamarca further to the south. In between those, I really liked Santa Maria, on the border of Tucuman and Catamarca province. But there are countless nice little villages in that area. None of them is particularly happening, but they make for a relaxing holiday.