I believe that research into both are equally important. (Sorry to be sitting on the fence here.)
Researching our oceans can give us immense information regarding what's happening on earth right now, in terms of climate change and effects of industry/pollution. As does studying our planetary neighbours, such as Mars and Venus (especially Venus - google the runaway greenhouse effect if you are interested).
Researching outer space leads us closer to the ultimate...the TOE (Theory of Everything), joining quantum theory and relativity, which will lead to a leap in technologies. The main one, hopefully, being clean energy for all (bringing us closer to nuclear fusion, as opposed to fission, which is still relatively clean, and the burning of fossil fuels). Sounds a bit star trekky!