This illustration from the Lunar and Planetary Laboratory shows the approximate sizes of the planets relative to each other. Note that the planets are not shown at appropriate distances from the Sun.

This online computer game deals with why allosaurs hunted as they did, as well as how. The student needs to balance the need for food for energy and growth with the risk of being savaged by one's potential prey or killed outright by another allosaur. The "Big Al" starts out as a 0.2 kg hatchling and ends up as a hunter of sauropods and a parent to the next generation of allosaurs. On this Starting Point page, users can access information about the exercise's learning goals, context for use, teaching notes and tips, teaching materials, assessment ideas, references and topics covered.

Through a higher-order integration of concepts and observations, students can combine information from several field labs, all discussed in the Starting Point collection, to construct an overall geologic history of the local region. This site details the learning goals, teaching notes and materials, method of assessment, and context of use of this lab. It also provides links to additional references and resources.

In this activity, students write an essay on the history of scientific discoveries in the field of dinosaur paleontology. The essays are then evaluated via Calibrated Peer Review. On this Starting Point page, users can access information about the exercise's learning goals, context for use, teaching notes and tips, teaching materials, assessment ideas, references and topics covered.

Examine geological evidence found in fossils, rock deposits, and ancient mountains that supports the theory of continental drift in this interactive activity adapted from the Exploratorium.

This page describes a geologic timescale poster available for purchase. The site also contains an interesting essay: "A Galactic Orbit Model for Periodic Mass Extinction," discussing how clusters of impacts could cause periodic mass extinctions.

This Starting Point exercise asks students to describe and interpret an image of folded strata at Dent De Morcles. There are several questions students must address with respect to the image. This Starting Point website includes suggestions for using this technique, as well as teaching notes, learning goals, and extensive additional resource links and references.

This sub-site of the University of California's Museum of Paleontology contains very detailed section on the Precambrian time period. The site includes a clickable timescale with detailed descriptions of the Hadean, Archean, Paleoproterozoic, Mesoproterozoic and Neoproterozoic time periods.

The Rockies are fifteen hundred kilometers, or one thousand miles, to the east. The cause must be the tectonic plate that built these mountains. Its name is Farallon. Farallon started off normally enough. It plunged beneath the North American Plate at a forty-five degree angle. This process sprouted volcanoes to form the Sierra Nevada in what is now California. Next, mantle motions pulled North America westward over Farallon, and the plate scraped along the bottom of the continent - for fifteen hundred kilometers. As North America continued its westward trek, Farallon settled to the bottom of the mantle.

Earth and all the other planets and moons of our Solar System have been continuously pelted by asteroids and comets ever since their formation. On Earth, wind and water have eroded away most of the evidence; various other geologic processes have concealed it; oceans and vegetation now cover much of the rest. This activity will help your students understand how NASA scientists are discovering evidence of impact craters through satellite images and technology, which enables us to see landforms that we can't see with our eyes alone. Students consider the sudden release of a tremendous amount of kinetic energy when an extraterrestrial object strikes the Earth. They write about the effects that such a collision might have on the land, atmosphere, water, and living things. Students then read descriptions of the actual effects of impact events and the evidence these leave behind. In small groups, they study satellite images that show possible evidence of impact events. They select one or two of these images to interpret for the class. In their interpretations, they explain how the image does or does not show evidence of an impact event. To demonstrate their understanding of the role of impact events in shaping the Earth, students write a series of guidance questions for a field expedition to determine whether or not a given landform is an impact crater.

In this activity, the authors use a series of games to help students identify and answer questions about fossils. The game grows more complex over time as the instructors add rules and phyla to identify. The game begins as a simple "spelling bee" type competition to identify fossil arthropods. Each week, a new phylum and more kinds of questions are added, along with game pieces like dice, trilobucks, and a board that represents geologic time. On this Starting point page, users can access information about the exercise's learning goals, context for use, teaching notes and tips, teaching materials, assessment ideas, references and topics covered.

In this interactive activity from the Children's Museum of Indianapolis, Indiana, examine a piece of the ancient Borden Sea in what is now central Indiana. Explore the types of fossils found there and the clues they offer to ancient life on Earth.

This site from SERC's Starting Point presents sample Gallery Walk questions about time and earth history. Topics that students are asked to write about include the manner in which geologic, climatic, and floral events shaped the evolution of animals through the PreCambrian, Paleozoic, Mesozoic, and Cenozoic Eras. The questions are organized according to the cognitive level at which students are engaged, using Bloom's Taxonomy.

This site provides animations, images, interactive maps and videos that can be used to teach about the concept of geologic time. Visual resources cover some specific topics of earth history including plate tectonics, continental drift, relative age dating and paleontology. These resources are appropriate for an introductory level geology course.

This website contains a detailed, annotated geologic time line. The timeline spans Precambrian to Quaternary time detailing geologic developments and life forms of the time. Descriptions contain clickable terms and images revealing detailed information on specific life forms.

This tutorial will help students learn and understand the concepts of geologic time and the age of the Earth. They will investigate the geologic time scale and learn about the use of index fossils and radiometric dating to determine the age of rock formations and fossils.

This is the webpage of an introductory Earth History course at the University of Michigan. The course focuses on basic geologic language and principles, earth materials, depositional environments, geologic time, plate tectonic and evolutionary theory. The website contains online study guides, lecture notes, homework, and useful links.

This spiral graph visualization, which includes both marine and terrestrial components, represents 4.5 billion years of geologic time. Stratigraphy, paleontology, and geochronology study results provide evidence in support of this old earth. This graphical representation is from an article called Age of the Earth.

This site features Flash and Windows Media animations that illustrate various aspects of geologic history. They depict fossil cast formation, the Big Bang and earth through geologic time, the significance of isotopic dating techniques, and views of dinosaurs. These resources are suitable for use in lectures, labs, or other teaching activities.