Every year, National Geography Awareness Week provides an opportunity to reflect on the significance of place and how we affect it. One fantastic way to explore geography is from above. When viewing the Earth from a high altitude or even from space, we can begin to see and record natural and man-made features and events. We can see the remains of civilizations and the aftermath of disasters.
For the 100th anniversary of the National Park Service in 2016, the National Geography Awareness Week theme was Explore the Power of Parks. Over the years NASA has collected imagery from space of our National Parks that help to document changes over time.
At Glacier Bay National Park & Preserve a view from above helps us to see how ice is slowly retreating. The same is true at Montana’s Glacier National Park where its predicted glaciers will no longer exist by 2030. Photography from space can also illuminate how seasons affect our parks like those at the Great Smoky Mountains National Park. We can even see the aftermath and recovery of large disasters like the violent eruption of Mt. St. Helens in 1980 or the devastating wildfires at Yellowstone National Park in 1988.
Custom Image Caption
Glacier Bay National Park & Preserve. Much of the ice that made up the Park has retreated into the Bay. Image: NASA
Custom Image Caption
Landsat 5 captured this image of Montana’s Glacier National Park on August 17, 1984. Scientists predict the park will be glacier free by 2030. In this image, most of the blue color is "permanent" snow and ice largely in the Blackfoot-Jackson basin. Image: NASA
Custom Image Caption
Landsat 8 captured this image of Montana’s Glacier National Park on August 23, 2015. Scientists predict the park will be glacier free by 2030. This image shows a loss in "permanent" snow and ice largely in the Blackfoot-Jackson basin represented in blue. Image: NASA
Custom Image Caption
Different seasons can be seen in this series of images of the Great Smokey Mountains National Park captured by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. Image: NASA
Custom Image Caption
A satellite image of Mt. St. Helens from 1979 prior to its eruption, captured by a Landsat satellite. Earlier Landsat images are false-color (vegetation is red) because earlier Landsat satellites could not “see” blue light. Image: NASA
Custom Image Caption
Mt. St. Helens following its eruption in 1980. Image: NASA
Custom Image Caption
A satellite image of Yellowstone National Park from 1987. In the summer of 1988, lightning- and human-ignited fires consumed vast stretches of the Park.
Custom Image Caption
Satellite image that shows Yellowstone during the 1988 fires.
A satellite image of Yellowstone National Park from 2011. In the summer of 1988, lightning- and human-ignited fires consumed vast stretches of the Park. This image illustrates the Parks recovery from those wildfires.
How have some of these images been captured? Landsat satellites have been monitoring the Earth since 1972 and have covered tens of billions of square kilometers of this place we call home. Eight Landsat satellites have been launched to date, although Landsat 6 was lost at launch in 1993. The most recent Landsat, Landsat 8, launched on February 11, 2013.
Earth-imaging sensors on the Landsat satellites have advanced over the years to provide higher resolution imagery and layers of information. The first three satellites used a Multi-Spectral Scanner (MSS). The fourth and fifth satellites carried an MSS as well as a more advanced sensor called the Thematic Mapper (TM). The Museum has a model of each of these sensors.
MSS could produce images of the Earth that cover an area of about 34,000 square kilometers (about 13,000 square miles) with a resolution of about 80 meters (260 feet). The MSS, acquired data in both visible and infrared wavelengths, and employed an oscillating mirror to scan the Earth beneath the spacecraft. TM could resolve features about three times smaller than earlier Landsat instruments and could collect data in more wavelength bands.
The Enhanced Thematic Mapper Plus (ETM+) was used on Landsat 7, while Landsat 8 uses a sensor called the Operational Land Imager (OLI). The advances in technology can be seen in these two images of the Grand Canyon, one captured by Landsat 1 and the other Landsat 8.
Landsat 1 captured this image of the Grand Canyon.
This image of the Grand Canyon was captured by Landsat 8.
The Landsat satellites are not alone. A variety of satellites orbit our planet every day. They’re designed to observe different features of our planet from mapping ocean currents to monitoring weather. Combined they provide us with a greater understanding of the natural processes and human activities that shape our planet.
We encourage you to visit your closest National Park and enjoy the scenery from the ground while also considering the view from space. How do you think that scenery may change in 100 years from now? Or even 500 years from now?