Astronauts on the International Space Station used a Nikon camera with an 800mm lens to take this photo of Shiveluch Volcano on Russia’s Kamchatka Peninsula. It shows the ash and steam plumes from an active eruption as well as the eroded remains of pyroclastic flows from previous eruptions. This is just one of the 1,500,000 astronaut photos Nasa puts to work by letting students across the United States conduct their own Earth science investigations.
Nasa created Expedition Earth and Beyond to give students and teachers hands-on experience using space-based images to understand Earth sciences rather than relying on static textbook explanations. Teachers can take an inquiry-based approach by asking students to compare images of features taken at different times, from different angles, and at different locations. As the students observe the similarities and differences between the images, they reach their own conclusions about plate tectonics, glaciers, clouds, and more. As explained by EEAB Director Paige Graff in a recent Nasa press release:
Along the way Expedition Earth and Beyond gives students a feel for how professional scientists use images from space in their research. But it can go further than that. The program is run by Nasa's Astromaterials Research and Explorations Science group at the Johnson Space Center - the scientists who maintain Nasa’s collection of Moon rocks, meteorites, and space dust. Through their outreach program the scientists conduct free online webinars - one event last year attracted 1,500 students - during which students can ask a Nasa expert questions about Earth science and using space images. For a more in-depth experience, Ares scientists mentor student teams through a month-long research project. Students can even request fresh images of Earth taken by Nasa’s astronauts on the International Space Station.
Astronaut photography offers professional scientists unique advantages over traditional satellite-based remote sensing. Polar-orbiting satellites typically pass over any given spot at the same time of day and point their cameras straight down. Astronauts on the ISS can aim their cameras towards interesting features and time their shooting schedule for different lighting conditions. They also have a variety of lenses that can capture wide vistas or zoom in for detailed shots. With over 1,500,000 astronaut images in Nasa’s public database, you can find many examples of features on Earth’s surface or its clouds taken at different times of day. This gallery of cumulonimbus clouds, for example, shows how space images can help you learn about these intense storm systems.
Of course astronaut photography has drawbacks compared to traditional satellites - it isn’t as consistent and predictable. Different astronauts take the pictures with different cameras at different points in the space station’s orbit. An image may not be oriented with north at the top. The photo might be taken from straight above or at an extreme angle. One image may use a relatively wide 50mm lens while another might use an extreme 400mm telephoto lens. This variability makes some subjects difficult to study using astronaut photos. Can you find evidence of drought’s effects on Southern California’s Salton Sea in this gallery, for example, or are the differences between the images too great?
Expedition Earth and Beyond’s curriculum materials don’t stop at the planet Earth. Planetary scientists often compare geological features on planets, moons, and other objects throughout the Solar System. Different worlds have unique combinations of gravity, atmosphere, and geological activity that make mountains and craters and volcanoes appear different. Scientists learn about a planet’s geology by studying those differences. At the same time, the similarities improve our understanding of out own planet. One of the EEAB’s student-led investigations, the Crater Comparisons Activity, introduces students to the ways impact craters vary on different planets. Here’s a sampling of asteroid impact craters on Earth, the Moon, and Mars.
Evergreen Middle School teacher Dennis Mitchell uses the EEAB program to introduce his 7th grade students to satellite imaging. In an article he wrote for the California Science Teachers Association, Mitchell said:
His students get their feet wet using space images for classroom research. They use the EEAB’s curriculum to study Earth and request astronaut photographs before they move on to taking part in Nasa-sponsored programs to explore Mars.
All images of Earth courtesy of the Earth Science and Remote Sensing Unit, NASA Johnson Space Center via the Gateway to Astronaut Photography. Lunar image from the Apollo Lunar Surface Journal (Credit Nasa/JSC, Kipp Teague). Mars image from the High Resolution Imaging Science Experiment (Credit Nasa/JPL/University of Arizona)