I believe that the true role of a scientist is to find alternative ways to make our world a safer and healthier place. Be it studying the deepest parts of the ocean or the limitlessness of the universe, we have seen that some times the things we need to solve problems come from very weird places.
The role of scientists is to do as Galileo did and discover ways to unravel mysteries of the universe. This requires thinking of effective experiments; looking closely at data; analyzing data effectively among other things. I'm reminded of a solar physicist of my acquaintance who approaches map reading with the same skills that he approaches analyzing daily data transmitted from SoHo ... he stares indefatigably to find the order and sense in the collected patterns [granted, maps offer known patterns, while images of the Sun offer unknown patterns].
Scientists ask the questions "Why?" and "What if...?". A scientist is a seeker of cause and effect. The more formal aspects of research - hypothesis, dependent and independent variables, controls - have developed as assurances that the cause and effect that are observed are truly linked, and not just an accident or an interpretation.
Science is everywhere. Some scientists seek out knowledge about the Earth and the life on it, some about the universe, some work on artificial things such as man-made materials or computer algorithms. However, the search is always on for an increase in knowledge, the making of connections in a cause-effect pattern, and an exchange of information with others.
Science is the search for knowledge of the universe. Science in its best form is dispassionate, methodical and rational. This is often not the case as scientists also have to eat, and sometimes end up working for companies or groups that want a specific scientific result regardless of reality. A good scientist asks questions, tests hypotheses, and keeps humanity and ethics in mind when conducting research.
Scientists should seek to explain, not seek evidence for what they believe is true. A real scientist goes into the process with an open mind. He may have a theory, but he does not just look for evidence to back up the theory. He is open to all possibilities, including being proven wrong!
The true goal of scientists should be the discovery of new knowledge. The whole purpose of science is to better understand the processes that control the workings of the natural world. A true scientist is someone who is trying to discover more about those processes.
There are two types of science... goal-oriented science and blue-sky science.
An example of goal-oriented science is finding the cure for AIDS. We need a cure and we pay scientists to focus on that until they find one. They have a specific objective and try to work towards it.
Blue-sky science is where the research doesn't have an objective because the objective is an unknown.
Ultimately, scientists try very very hard to discover the provable truth about the world (or universe) in which we live. Nothing more and nothing less.