According to Wikipedia, a paradox is:
a statement that, despite apparently sound reasoning from true premises, leads to an apparently self-contradictory or logically unacceptable conclusion. A paradox involves contradictory yet interrelated elements that exist simultaneously and persist over time.
My question is, do paradoxes necessarily require a successful explanation in order to be considered a paradox? In other words, is there such a thing as an unexplained paradox? Or that would be called a puzzle, a problem, or a mystery? I am particularly interested in paradoxes in science.
Notice that there are of course a multitude of problems in science that have not been resolved, but they do not necessarily have to be paradoxes in the sense defined above.