Earth Science: Geology, the Environment, and the Universe

Unit 8: Beyond Earth

WebQuest Projects 2

Saturn Revealed: The Cassini-Huygens Mission to the Ringed Giant

When Italian astronomer Galileo Galilei first turned his telescope towards Saturn in 1609, he could scarcely have imaged how different from his own that distant world would turn out to be. Saturn is circled by a billions of glittering ice and rock particles, which form a dazzling ring system around the planet. Scientists believe that shrouded within the dense, suffocating atmosphere of hydrogen and helium gas lies a small, rocky core, roughly the size of Earth. 31 moons orbit the gas giant, which is more than nine times larger than Earth. Despite its great size, Saturn rotates at an astonishing rate, zooming through a day in just over ten hours. With the second-largest planetary mass in the solar system and a density so low that the planet could theoretically float on water, Saturn is truly a mysterious planet, vastly different from Earth.

Galileo's early observations of Saturn generated more questions than answers. His work spurred other scientists of his age, including Dutch astronomer Christiaan Huygens and Italian astronomer Giovanni Cassini, to investigate the ringed giant. Earth-based studies would continue for more than 300 years after these early astronomers made their first observations of Saturn. In 1979, however, space-based observation of the Saturnian system became a reality. Data collected by the unmanned spacecraft Pioneer 11 in 1979, Voyager 1 in 1980, and Voyager 2 in 1981 shed new light on many of Saturn's mysteries. In July, 2004, the Cassini spacecraft reached Saturn following a seven-year journey. The Cassini-Huygens mission, named in honor of those astronomers who furthered human understanding of Saturn in the 1600's, will span four years and combine the resources of 16 countries. When the mission is completed, scientists will have a new understanding of the ringed giant of our solar system.

Your task in this WebQuest is to investigate Saturn through data and images collected during the Cassini-Huygens mission. You will learn about the unique characteristics of the Saturnian system, including the rings which encircle the planet, the moons which orbit it, and the nature of the planet itself. You also will investigate the Cassini spacecraft, the scientific instruments it carries, and the purpose of the Cassini-Huygens mission. Answering a series of questions about the mission and the planet will guide your research into the topic. You will use the information you gather to create a multimedia presentation about the Cassini-Huygens mission and the Saturnian system, including data and images gathered by the Cassini spacecraft and the Huygens probe. The purpose of this presentation is to organize and display information which shows what scientists are learning about the second-largest planet in our solar system.

The Web sites given here will help you answer questions about the Cassini-Huygens mission and the Saturnian system. The information you gather will help you create a multimedia presentation about the topic.

http://saturn.jpl.nasa.gov/news/features/saturn-story/index.cfm
This Web site offers a wealth of information about Saturn and the Cassini-Huygens mission. Visit the site to learn about the characteristics of the planet and its ring system and moons, as well as the spacecraft that have studied it beginning in 1979.

http://www.nasa.gov/mission_pages/cassini/main
This site provides an array of articles, pictures, and multimedia features describing various aspects of the Cassini-Huygens mission. View the timeline to learn about the path Cassini took after leaving Earth in 1997. The spacecraft and instruments button leads to detailed information about the Cassini craft given in pictorial form.

http://spaceflightnow.com/cassini/index.html
Numerous articles at this site provide information and pictures related to the Cassini-Huygens mission. Topics include Saturn's rings and polar regions, as well as its moons Titan, Iapetus, Dione, Tethys, and Rhea.

http://www.planetary.org/saturn/
This site offers the latest images returned from Cassini, as well as photos from Voyager missions and the Hubble space telescope. Photos include images of Saturn's rings and moons, atmospheric phenomena, and the planet itself.

http://www.space.com/cassini/
Interesting articles at this site include "Surfing Titan: Huge Waves Possible on Saturn's Moon", and "Titanic Discovery: Earth-like Weather and Methane Rain."

http://www.ssd.rl.ac.uk/news/cassini/
This Web site offers information, pictures, and artist renderings of the Cassini craft and the Huygens probe, as well as facts about Saturn, Titan, and the launch of the Titan rocket which carried Cassini into space.

http://en.wikipedia.org/wiki/Cassini-Huygens
Read about the Cassini-Huygens mission at this site. Important events and discoveries of the mission are highlighted, including a test of Einstein's theory of general relativity.

http://www.the-planet-saturn.com/
Test your knowledge of Saturn with quizzes at this site which also offers a detailed "Cassini Mission to Saturn" fact sheet published by NASA.

http://www.solarviews.com/eng/cassini.htm
This site provides a multitude of pictures related to Saturn, including clear photos and descriptions of Saturn's major moons.

http://saturn.jpl.nasa.gov/kids/amazing-dvd.cfm
Visit this site to learn about the project to send signatures of people from over 80 countries into space on the Cassini spacecraft.

1-2 weeks to research the topic, answer the question set, and design the multimedia presentation

Read the following questions before beginning your research. As you explore each Web site, look for answers to the questions.</p>

1. Saturn has been studied by four space-based craft, including Pioneer 11, Voyager 1, Voyager 2, and the Hubble space telescope. Describe some interesting features of Saturn that data from these spacecraft have revealed.
2. Saturn's rings are a unique, yet not completely understood planetary feature. Scientists hope data from the Cassini-Huygens mission will help explain how the rings formed and how they maintain their orbit. Describe what scientists currently know about Saturn's rings, and describe how they believe they formed.
3. The Cassini-Huygens mission is named after astronomers Christiaan Huygens and Giovanni Cassini. Describe the contributions made by these two men who studied Saturn in the 1600's.
4. The Cassini spacecraft is one of the most massive and powerful craft ever sent into space. Describe the Cassini spacecraft, and identify some of the instruments it carries.
5. The Cassini spacecraft did not fly directly to Saturn. Instead, flight engineers made use of a technique called "gravity assist," which allowed the spacecraft to use less fuel to reach its ultimate destination. Describe the general path the spacecraft took from its launch in 1997 to its arrival at Saturn in 2004. Include dates in your description.
6. An important component of the Cassini-Huygens mission involves sending the Huygens probe through Titan's atmosphere, and attempting to land the probe on the surface of this moon. Titan is the largest of Saturn's 31 moon's, and the second-largest moon in the solar system. Why is Titan of particular interest to space scientists?
7. Some of Saturn's moons have unusual features that are of interest to space scientists. Describe the unique characteristics of the moons Mimas, Iapetus, and Phoebe.

Finally, create a multimedia presentation which shows what scientists are learning about Saturn and its satellites through the Cassini-Huygens mission. The scrapbook should provide relevant and factual information. Consider including the following elements in your presentation:

• images of the Cassini spacecraft and descriptions of its structure and the type of equipment it carries
• photographs and descriptions of the launch in 1997
• pictures of Saturn taken by the Cassini spacecraft and descriptions of specific physical features of the planet
• images and/or artist renderings of Saturn's ring system and a description of the components found within it
• photographs showing the yellow and gold bands of Saturn's atmosphere and a description of what causes them
• images of some of Saturn's moons and descriptions of any unusual physical features
• artist sketches and descriptions of what the surface of Titan might look like

While completing this WebQuest, you gained knowledge about the Saturnian system. As you gathered information to answer questions about the topic, you learned about the purpose of the Cassini-Huygens mission, and how data from this mission is helping space scientists redefine their understanding of Saturn, its ring system, and its numerous moons. You used research, writing, and creative skills to develop a multimedia presentation which highlights what scientists are learning about Saturn from the Cassini-Huygens mission.