In 1968, the Apollo 8 astronauts caught their first glimpse of Earth rising over the barren surface of the moon. Their full-color photo of our home planet is serene, majestic and breathtakingly beautiful, and is the iconic image of the environmental movement. My 53 days spent working in orbit only heightened my appreciation of Earth’s beauty and the importance of protecting our planet. On Earth Day, it is especially worthwhile to acknowledge that today and every day NASA’s spacecraft are hard at work, enhancing our abilities to observe, understand and predict our complex world.
We are all familiar with the space agency’s extraterrestrial pursuits, using cutting-edge instruments to explore planets, moons, stars and galaxies. Some of NASA’s greatest discoveries, however, occur when it focuses technology homeward. In 1994, for example, I flew on two shuttle missions observing planet Earth, using advanced radar imaging to study changes in the global environment, assessing vegetation, snow cover, wetlands, geologic features, volcanic eruptions, ocean currents, and earthquake faults. Today, NASA’s Earth-observing satellites track weather patterns and natural disasters, map infectious disease outbreaks, chart sea ice, and pinpoint pollution sources.
NASA’s spacecraft provide hard data that guide citizens and policy makers toward informed decisions about the environment. Protecting Earth’s ozone layer is a great example of long-term success. NASA’s Total Ozone Mapping Spectrometer provided space-based images of the ozone hole that sparked concern worldwide and prompted the international treaty known as the Montreal Protocol. Since 1987, more than a hundred countries have agreed to limit chemicals known to deplete the ozone layer, which shields us from the sun’s dangerous ultraviolet radiation. The ozone’s full recovery is still decades away, but measurements from NASA’s Aura satellite show levels of the harmful compounds are starting to decline.
This month, sensors on board NASA’s Aqua satellite gave firefighters a top-down view of wildfires burning in Oklahoma and Texas. Just last month, the EO-1 satellite provided disaster relief planners with an overhead view of the bulging Red River as flood waters rose in North Dakota and Minnesota. Also in March, the Landsat 5 satellite, a joint effort between NASA and the U.S. Geological Survey, enabled scientists to track volcanic plumes and ash from repeated eruptions of Alaska’s Mt. Redoubt.
The ability to track changes in Earth’s vegetation cover has far-reaching benefits, especially as plant life responds to climate change. At NASA’s Ames Research Center in California, researchers use satellite data to follow the growth of invasive plants that burn more frequently and rapidly in wildfires than native species. Climate also influences the spread of infectious diseases like cholera. NASA has partnered with agencies such as the Centers for Disease Control to provide satellite data that help predict where and when an outbreak may occur.
Growing populations in desert cities have increasingly taxed scarce water resources. Satellite images of Las Vegas, collected over 25 years, track urban growth and help planners anticipate water demand in this arid region. Measurements from the TOPEX/Poseidon and Jason-1 satellites kept watch over water levels in reservoirs around the world.
Satellites also measure the intensity and extent of carbon emissions from industry, biomass burning and natural wildfires. These measurements give us the most objective, accurate picture of Earth’s carbon cycle. The data, in turn, could save hundreds of billions of dollars over the coming decades by helping policy makers identify the most cost-effective environmental protection measures.
Improving our understanding of the environment is another way that investing in space exploration improves our lives on Earth, but NASA’s observation program is only as healthy as its budget. We must give NASA the appropriate funds, not only for its mission to explore beyond our planet, but also so the agency can develop and launch the latest tools and quickly make public the returned data.
From the unrivaled vantage point of space, I saw Earth as a haven, our unique oasis in a harsh universe. Earth Day reminds us of how our exploration of that universe will help us monitor and protect that most precious world — our home planet.
For this astronaut, every day is Earth Day.
Tom Jones is a planetary scientist and veteran astronaut. He flew four space shuttle missions to conduct Earth and space science, and helped deliver the U.S. Destiny laboratory to the Space Station. Jones is a consultant, speaker, and author, and serves on the boards of the Coalition for Space Exploration and the Association of Space Explorers. His latest book is Planetology: Unlocking the Secrets of the Solar System.