Choosing a science essay topic can be difficult because science encompasses so many specialized areas of study. There is life science, physical science, earth science, chemistry, biology, physics and astronomy, to name a few. If you are having trouble deciding, try to narrow the list down to what you are interested in the most, and search the Internet for government organizations or universities and colleges that fund summer camps and/or run essay contests.
The National Aeronautics and Space Administration (NASA) has a website full of ideas for good science essay topics. One of photo and essay contest encourages students to learn more about solar system geological processes. This is a good essay topic for those students who like to conduct scientific experimentation in an outdoor environment.
The U.S. Department of Energy has a website offering many different scientific topics that can be explored and put into essay format. For example, if you are interested in life science, a good essay topic might be to describe the primary oxygen-transporting protein found in red blood cells. If you are more interested in earth sciences, you might want your essay to discuss the common name for the rising and falling of sea levels in reaction to the power expended by the moon and sun.
Other government organizations that offer good essay topics include the Princeton Plasma Physics Laboratory which runs summer science camps for middle school students and a science bowl in which students compete. They also have an annual essay contest with varying themes, such as: "Combustion, hybrid, or electric? What type of engine would you choose?" Another one is: "Re-design the energy use in your city. What would you do to make your city use clean and efficient energy sources?"