This document presents a number of theories, both plausible and implausible or even humorous, for the extinction of the dinosaurs. Links to a glossary are embedded in the text. A reading list and links to related sites are also provided.

The transit of Venus is a rare astronomical event that has been well documented throughout history. The most recent transit occurred in June of 2004, and the one before that took place more than 100 years earlier in 1882. This site from the South African Astronomical Observatory provides information and first-hand observations of the 1882 event from Wellington, South Africa. Just prior to the event, an observatory was erected at the Huguenot Seminary for girls, and some of the historical observations made from that site in 1882 are provided here for your perusal.

This article and included graphs,from the web site accompanying the FRONTLINE NOVA special What's Up with the Weather?, reveals how atmospheric carbon dioxide, methane, and nitrous oxides from coal- and oil-burning power plants, cars, and other fossil-fuel-burning sources have climbed along with the world population, with as yet unknown effects on the climate system.

This video adapted from the Valdez Museum & Historical Archive, explores what happened during the Great Alaska Earthquake of 1964 through original footage, first-person accounts, and animations illustrating plate tectonics. ***Access to Teacher's Domain content now requires free login to PBS Learning Media.

This movie shows a total eclipse of the Sun which occurred in 1994. It is accompanied by a link to a written description of the Sun's physical characteristics.

This NASA page is an image set illustrating the 20g centrifuge at the Ames Research Center. The photographs include two of human subjects strapped in the place at one end of the centrifuge arm.

The Two Micron All Sky Survey at IPAC website provides an image gallery of the solar system's objects, Jupiter's moons, H II regions, star formation regions, and reflection nebulae, open star clusters, globular star cluster, young stellar objects, planetary nebulae, supernova remnants, various IRAS sources, galaxies, as well as galaxy groups and clusters.

On July 14, NASA announced the public release of a huge collection of images (1.9 million) from the Two-Micron All Sky Survey (2MASS), the most thorough census of stars ever made. Using two automated, 51-inch telescopes, one in Arizona and the other in Chile, the three-year-old survey has so far taken images of half a million galaxies and 162 million stars. By its completion, the survey's catalogs will contain more than 300 million objects. A sampling of these images has been placed online at the 2MASS site at the Infrared Processing and Analysis Center (IPAC) at the California Institute of Technology. The twelve-page gallery contains some amazing images, including the center of the Milky Way, the Sombrero galaxy, the Crab Nebula, and the Dark Nebula, offered as large thumbnails which link to a full-sized image. Users can learn more about 2MASS at the survey's homepages at Caltech and the University of Massachusetts.

In this physics activity, learners build their own rockets out of film canisters and construction paper. Learners discover how a chemical reaction (from a mix of water and Alka-Seltzer) creates gas pressure to propel the craft. The activity explores the three states of matter and Newtonäóťs Laws of Motion.

In this activity, learners build small indoor paper rockets, determine their flight stability, and launch them by blowing air through a drinking straw. This lesson plan includes procedures for the two part activity, background information, diagrams for making Ares 1 paper rockets, discussion questions, extensions, and black-line masters for learners.

Students see firsthand that stars and constellations are not arranged in a flat, 2-D pattern in this Moveable Museum unit. The five-page PDF guide includes suggested general background readings for educators, activity notes, step-by-step directions, and a Big Dipper map. Students make their own 3-D models of the Big Dipper using readily available materials and examine their models, observing the 3-D constellation from new perspectives.

A 2-D map is a great guide here on Earth—and virtually worthless for finding your way around in outer space. Take a 3-D look at mapping our solar system and universe. This Moveable Museum article, available as a printable PDF file, looks at how astronomers use data to create 3-D models of the universe. Explore these concepts further using the recommended resources mentioned in this reading selection.

This web site, hosted by the University of Chicago Dept. of Astronomy and Astrophysics, is an image gallery of the Yerkes 40 inch refracting telescope--the largest refractor in the world. It includes views of the telescope, the machinery that turns it, and the observatory building. Links go to other parts of the Yerkes website.

This resource introduces students to the Dry Valleys of Antarctica, the largest area on the continent that is not covered by ice. Materials include a map and some brief facts about Antarctica and the valleys, such as size, location and physical properties (temperature, precipitation and others), and an online journal in which participants in the Dry Valleys Long-Term Ecological Research (LTER) project discuss what it is like to live and work there. The journal entries include descriptions of some of the organisms that inhabit the extreme environments of the valleys, physical features of the valleys, and the strange mummified bodies of animals such as penguins and seals that have been preserved in the cold, dry climate. There is also a glossary of acronyms used in the project and a set of links to other websites with additional information about the Dry Valleys.

The AAAS (American Association for the Advancement of Science Atlas of Population and Environment is an important analysis of the relationships between human population and the environment. Through text, maps, and diagrams, the Atlas illustrates how population affects the world's ecosystems and natural resources both in the short and long term. Using sophisticated mapping and graphic techniques, the Atlas provides quantitative analyses of the important links between such factors as human population density, rates of growth, migration, resource consumption, and technologies, and the state of the global environment. These links are explored across the content areas of natural resources, land use, the atmosphere, waste and chemicals, ecosystems, and biodiversity. The Atlas draws on research and data from a number of academic institutions and international organizations, including the United Nations, its specialist organizations and agencies; the World Resources Institute; the Center for International Earth Sciences Information Network; Oak Ridge National Laboratory; U.S. Geological Survey; and the UNEP-World Conservation Monitoring Centre. The Atlas was produced to provide a concise, science-based compendium of information on the population and environment topics so important to the realization of a sustainable future.

This web page provides information and contacts for the New Faculty Workshop hosted by the American Association of Physics Teachers (AAPT), in conjunction with the American Astronomical Society (AAS) and the American Physical Society (APS). This annual conference helps new faculty understand how students learn physics and astronomy and suggests how this information can impact a new professor's teaching methods. The workshop is intended for faculty in the first few years of their initial tenure-track appointed at a four-year college or university. Materials from presentations at the 2005 workshop can be downloaded through the "View attached documents" link below.

The "ABC" in question here happens to be the Australian Broadcasting Corporation and they have come up with a smashing collection of science podcasts. Visitors can sign up to receive new podcasts via RSS feed, but they should definitely test the waters here by listening to any one of Dr Karl's "Great Moments of Science" or an edition of "Talking Science", which features interviews with various luminaries in the worlds of science. Further on down the homepage, visitors will encounter programs that deal with the mind ("All in the Mind"), the world of occupational health ("Life Matters") and the philosophical musings of thoughtful people ("Ockham's Razor"). Overall, there is some very delectable material here, and one can imagine that such podcasts could be passed along to science classrooms everywhere.

This tutorial explains some of the techniques developed by astronomers to determine the distances of objects we see in the sky. Links to additional information are embedded in the text.

This site presents graphic plots of solar wind and magnetic field data from the Advanced Composition Explorer (ACE) spacecraft.

This Astronomy Picture of the Day shows a test in which a small satellite was tethered to the Space Shuttle in 1992. Numerous wide-ranging links provide further information.

This Astronomy Picture of the Day (APOD) image shows a laboratory test of the ion drive engine used to propel the Deep Space 1 exploratory probe across the solar system in 1998. The site includes a description of how the device works and provides links for related information.

This APOD page features the first confirmed image of an extrasolar planet orbiting a sun-like star. Text and numerous links provide additional information; one link goes to the press release of the confirmation.

This Astronomy Picture of the Day depicts the Himalayan mountain range in Nepal. The image was taken from the International Space Station. Links provide background information about Skylab, the Himalayas, and plate tectonics.

This Astronomy Picture of the Day shows the "dust flaps" that Apollo 17 astronauts jury-rigged on the lunar rover. The site describes the origin of lunar dust and provides links for further information.

This website is home to the Arizona State University (ASU) Mars Education Program. This program includes information about the MSIP (Mars Student Imaging Project), student visits to the Mars Space Flight Facility, educator workshops held at ASU and other national sites, and Mars hands-on activity guides. Red Planet Connection is a quarterly publication, which stimulates children's interest in science through the topic of Mars and Mars missions. The educator guides provide Mars-related information and activities for classroom use, including teacher resources, lessons, and information about Mars Surveyor, Mars Pathfinder, and Mars Global Surveyor. The website also covers ASU's involvement with the Mars program, including the Thermal Emission Spectrometer (TES).

The COSEE network promotes a better understanding of the key role the ocean plays in global environmental cycles and processes. COSEE activities highlight the contributions ocean-science researchers make to scientific knowledge in these important areas. Each COSEE represents one or more ocean science research institution, an informal science education organization, and at least one affiliate organization representing the formal education community.

This web page, authored and curated by David P. Stern, provides a non-mathematical introduction to modern magnetometers that depend on the saturation of magnetic materials. Applications include the observation the very weak magnetic fields in space and a 1979 experiment on the effects of cigarette smoking and the damage caused by asbestos. This is part of the site "The Great Magnet, the Earth". Also available in Spanish, German and French.

This site answers several common questions about rainbows, their formation, and their appearance. Diagrams along with descriptions are provided in each section. Example experiments are included.

Children learn how seasonal weather changes affect everything, from the behavior of animals to the way we dress and play.

In an investigation called "Shape It!" learners craft tiny boats out of clay, set them afloat on water and then add weight loads to them, in order to explore: how objects stay afloat in water; what the relationship is among surface tension, buoyancy, density and displacement; and how shape, size, and type of material affect an object's ability to remain buoyant. The introductory text discusses how heavy steel ships can float on bodies of water like rivers, bays and oceans.

This video segment adapted from First Light explains why the highest peak in the Pacific, Mauna Kea, is an ideal site for astronomical observations. Featured are new telescope technologies that allow astronomers to explore the universe in more depth. ***Access to Teacher's Domain content now requires free login to PBS Learning Media.

This module introduces the concept of biological absorption, storage and distribution of chemicals.

Academic Earth provides videos of lectures by top scholars in "Subjects" that range from Astronomy to Entrepreneurship to Religion, from "Universities" as celebrated as MIT, Berkeley, Harvard, and Stanford. Visitors must register to view the lectures, but registration is free. There are over 1500 video lectures available, with more being added everyday. In addition to viewing the lectures available by subject or university, visitors can choose by "Instructors" or by "Playlists". When visitors click on "Playlists" at the top of the homepage, they will see a list of lectures by theme, by several different instructors, and a grade given to the lecture series. A good example is the 6-part lecture entitled "Understanding the Financial Crisis" by four different instructors. The series is given a grade overall, in this case, an A-, and when visitors click on "See all 6 lectures" at the bottom of the series' description, they will be taken to the page with the links to the individual lectures, as well as shown the grade given each individual lecture. Visitors can even keep a playlist of their favorite lectures or download the lectures. Visitors should definitely check out the Frequently Asked Questions page, accessible by the "FAQ" link at the bottom of the website.

This website provides instructions on how to find and download images directly from the WISE archive. Anyone with an internet connection now has free access to high-resolution infrared images from the WISE mission. These instructions explain how to get the images you want, without using complex terminology and options that may be difficult for the layperson to navigate.

In this activity, students research scientific discoveries that happened by accident in the past, and learn how gamma-rays were discovered by 20th century scientists. In the process, students develop an understanding that science theories change in the face of new evidence. This acitivity is part of the "Swift: Eyes Through Time" collection that is available on the Teacher's Domain website.

In this video, an environmental technologist visits an abandoned coal mine in Kentucky to talk about how a remediation system (a series of settling ponds and treatment cells) is neutralizing the acid drainage flowing from the mine and keeping it from damaging a creek downstream.

This lesson plan was provided by the National Park Service Air Resources Division and prepared as a part of The Uplands Field Research Laboratory, Volunteer in Parks, and Interpretation of Science Project. The site includes lesson goals, background information (including the Definition of Acid Rain, Sources of Acid Rain, and Pollution Control Measures), and five coordinating lessons. There are also figures provided to go along with the activities to further illustrate the lesson.

This National Park Service (NPS) web-site contains lessons about acid rain. These lessons are designed to teach students about what acid rain is, what it does, why we should be concerned about it and how it is measured. The activities contain procedures, materials, time needed and follow-up questions for students to answer. The topics covered include gases contributing to acid rain, acids and bases, the pH scale, monitoring acid rain in the US and weather maps. There are maps, data, figures and worksheets to complement the lessons. Each lesson can be viewed individually or the entire plan can be downloaded as a whole.