Think about the people who are going to read your report. What level of education do they have? Are you writing your report for a teacher, a professor or the International Astronomical Union?
Knowing your audience helps you organize your research and determine what level of fact-finding needs to be done. If your audience is a group of professional scientists deeply involved with Saturn, you can simply write your report about the orbit itself. People unfamiliar with the planet will need more background information about the planet and its system of moons and rings.
Write to your audience's vocabulary. Writing a paper full of technical jargon is a waste of time unless your readers can understand it. Write in the language of your audience.
Be authoritative. To write your report well, you will need to gather some facts. Obtain at least three different sources for your information, as facts about the Saturnian system are quickly evolving thanks to the Cassini probe.
Even though your report will be on Saturn's orbit, which averages at 888 million miles, you'll want to be able to explain aphelion and perihelion. The Saturnian system features some very complex geometry thanks to the gravitation interaction among its many moons. You may want to touch upon that, too, as these interactions may have an effect on Saturn's overall orbit.
Answer any questions that arise in your own mind while you are doing your research. There are no shortcuts for good research, and good research will always show up in your report.
Engage your readers by posing a question -- "Have you ever wondered how close Saturn comes to the sun?" -- or with an enigmatic statement -- "Saturn actually glows in the dark, but no one knows just why."
Statements and questions like these are called hooks in advertising. They're effective in getting your readers' attention. References later in the text that remind your reader about the "hooking" statement will help keep them engaged in your report.
Resolve any questions or enigmas you've posed for the reader. Answer the question by the end of the report. If you've posed an enigma like the "glowing Saturn" puzzle, make sure that you present at least one accepted theory to satisfy the reader.
Avoid overloading your reader with facts. Try to explain concepts rather than quote facts, unless you are writing a purely scientific paper for a scientific audience. Facts can be interesting, but only if the reader understands the concepts behind them.
Make no mistake: you will need to state some facts. But a good report will do more than spout facts and figures. It will explain the Saturnian system to your readers and make them want to learn more about it.