First, basically what is science: Science is the concerted human effort to understand, or to understand better, the history of the natural world and how the natural world works, with observable physical evidence as the basis of that understanding1. It is done through observation of natural phenomena, and/or through experimentation that tries to simulate natural processes under controlled conditions. What Science Is.
Second, what is not science: 1. Science is not a process that can solve all kinds of problems and questions. The realm of science is limited strictly to solving problems about the natural world. Science is not properly equipped to handle the supernatural realm (as such), nor the realm of values and ethics. What Science is Not.
Science is neither an invention of satan to tempt believers not is it a means of disproving beliefs and values, yet it seems doomed to constant misuse. Scientific examination begins with an observation and proceeds to an attempt to explain the observation in the natural world.
Science done improperly is not really science. Piltdown Man is often used as an example of the inability of science to come to objectively valid conclusions and why nothing science says can be believed. Actually, Piltdown Man was not science, it was and was intended to be a hoax. It was an intentional hoax and was proven to be so by scientific investigation of the fraud. All it illustrates is that scientists are capable of dishonesty and of being tricked. The answer to bad science is not to give up all attempts to make sense of the world around us, the answer is good science critically reviewed. Today's climate czars are often no more than the Piltdown hoaxers trying to force a consensus in place of peer review.
Who decides, and on what basis, what constitutes "natural phenomena?" Is it merely the frequency with which an event occurs that it somehow becomes "natural?" It it because it is observable to the human senses or by way of instruments that extend those senses? I firmly believe the word "natural" to be one of the most arbitrary ascriptions ever produced in human thought and language, much like the word "racist."
How does science know gravity is not an ongoing "miracle?" It doesn't. It chooses language that avoids such a word, but it has no scientific basis for doing so. It often operates under assumptions which it does not have the prerogative of asserting as wholly objective, not unlike certain Senators who believe it is wholly lawful to target conservatives under the tax code.