No matter how many times the sun rises over the horizon, there is always a chance that it won't. No matter how many times a shrimp and a golbi create a symbiotic relationship, there is always a chance that golbi will eat its partner. Every aspect of natural science is unpredictable, and this is why absolute certainty can never be  guaranteed. This is because in a sense, the things that natural science concern have a mind of their own. For our universe to exist like it does today, it must be perfect. So perfect, that its complexity  is on a level that which humans struggle to comprehend. The universe laughs at our attempts to explore space as we barely scratch the boundaries of our own solar system. How can we ever come close to being absolutely certain of outer space? With each passing year, the progress in the world of science doesn't compare to the vastness of what has yet to be discovered. In fact, with each discovery, more questions arise, making the quest never ending.