Essential Lens: Analyzing Photographs Across the Curriculum
Processes of Science: Mars, a Case Study #6031 Tenoumer Crater, Mauritania
Date: January 24, 2008
Location: Sahara Desert
Photographer: NASA’s Terra satellite
Source: NASA image created by Jesse Allen, using data provided courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team
Deep in the Sahara Desert lies a crater. Nearly a perfect circle, it is 1.9 kilometers (1.2 miles) wide, and sports a rim 100 meters (330 feet) high. The crater sits in a vast plain of rocks so ancient they were deposited hundreds of millions of years before the first dinosaurs walked the Earth.
Modern geologists long debated what caused this crater, some of them favoring a volcano. Closer examination of the structure, however, revealed that the crater’s hardened “lava” was actually rock that had melted from a meteorite impact.
Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) on NASA’s Terra satellite captured this image of Tenoumer Crater in Mauritania on January 24, 2008.
In this simulated-true-color image, the arid landscape appears in varying shades of brick red, brown, and tan. The crater’s outline is unmistakable, yet it doesn’t necessarily look like a crater; the light and shadows make it look more as if someone pressed a giant cookie cutter into the rock. In this image, the sunlight shines from the southeast (lower right), and the bright arc along the northwestern part of the crater is where the crater walls slope up to the rim. Around the perimeter, the relatively steep walls cast dark shadows.
Although it resides in ancient rock, Tenoumer is geologically young, ranging in age between roughly 10,000 and 30,000 years old. Once Tenoumer’s origin as an impact crater was understood, geologists began to wonder whether it resulted from a multiple impact event.
Tenoumer and two other craters, named Temimichat-Ghallaman and Aouelloul, occur along an almost perfectly straight line. A 2003 study tried to resolve the issue by examining the ages of these craters. By looking at chemical compositions of rocks, geologists can estimate when they formed. Examination of Tenoumer and Aouelloul craters showed that they formed at different times and, therefore, could not have resulted from the same impact event.
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Program 1 A Closer Look (video)
This introduction to the course models the process of analyzing photographs with teachers and students. Photography historian Makeda Best discusses the Focus In method with teachers, and educator Julie Keefe employs the method with students at a photography exhibit on "light and dark." Photography curator at the Portland Art Museum, Julia Dolan discusses how she carefully selects a set of photographs to tell a larger story.
Program 2 Witness (video)
Photographs bear witness to world events and help us to learn more about people, places, and situations -- historical and present day. Middle school teacher Donald Rose guides students in analyzing photos from school integration movements of the 1960s. Documentary film producer Ken Burns weaves photographs into historical narratives to bring the past to life. Photojournalist Louie Palu's photos take us deep into mines and war zones, and engage us with the individuals who take on those tasks.
Program 3 Lives (video)
Lives explores the story of human resilience and perseverance. Middle school teacher Donald Rose uses the Migrant Mother photos by Depression-era photographer Dorothea Lange to help students understand what elements a photographer chooses to focus on to create the greatest impact. Historian Linda Gordon, biographer of FSA photographer Dorothea Lange reveals Lange's role in engaging Americans in the plight of those who were most devastated. New Orleans documentary photographers Keith Calhoun and Chandra McCormick talk about the transformation of their photographs after Hurricane Katrina and working with young photographers to preserve the city's cultural heritage.
video 4 Evidence (video)
An image can show us otherwise invisible processes, previously undiscovered life forms, and dramatic change over time. High school teacher Rima Givot engages her students with highly magnified photos of mouse muscle to study genetically modified organisms. Scientist and photomicrographer Dennis Kunkel demonstrates the fascinating process of creating photographs of the microscopic world. Environmental photographer Gary Braasch reports on his worldwide travels to document the state of the planet through repeat photography.
Program 5 Story (video)
Every photograph tells a story: of struggle, of beauty, of community and culture. Social studies teacher Kim Kanof uses photos from the Protests and Politics collection to teach about protests around in the world in 1968. National Geographic photo editor Pamela Chen details the collaborative process of creating photo-based feature stories with design director David Whitmore. Iowa photographer Danny Wilcox Frazier discusses his work documenting the residents and images of marginalized communities across the United States.