World Space Week, designated in 1999 by the United Nations "to celebrate each year at the international level the contributions of space science and technology to the betterment of the human condition," starts Oct. 4, with events continuing until Oct. 10. This year's theme, “Remote Sensing: Enabling Our Future,” highlights Earth observation from space.
The U.S. Landsat mission, which celebrated it's 50th anniversary this September, has collected millions of images of Earth from space, from the satellite Landsat 1, launched in 1972, to Landsat 8, launched in 2013. Both Landsat 7 and Landsat 8 continue to orbit the Earth today, capturing images of the entire planet every 16 days.
The original mission was to gather information about the natural resources of the Earth, according to its founder, Secretary of the Interior Stewart Udall. Today, "Landsat satellites monitor forest health, mobilize food resources to drought-stricken areas, observe climate change impact on polar ice caps, monitor crop health and stress, measure the impacts of carbon escaping into the atmosphere, and map rates, causes, and consequences of land cover change," the United States Geological Survey (USGS) writes.
The sensors on these satellites capture more than your average Earth-photo. In addition to RGB (red, green, and blue) color, they are able to record near infrared, shortwave infrared, and thermal data, among other specialized observations. The resulting images are often not only scientifically valuable, as they allow scientists to reveal features our eyes cannot see, but also spectacularly beautiful.