Satellite images of Earth at night have been a curiosity for the public and a tool of fundamental research for at least 25 years. They have provided a broad, beautiful picture, showing how humans have shaped the planet and lit up the darkness.
Greenness is an important indicator of health for forests, grasslands, and farms. The greenness of a landscape, or vegetation index, depends on the number and type of plants, how leafy they are, and how healthy they are.
Industrialization has brought incredible societal advances and difficult pollution problems. From space, we can see skies clearing in some regions and darkening in others. The thin blue line of our atmosphere is still quite vulnerable.
Sea salt, volcanic ash, dust, wildfire smoke, and industrial pollution are types of airborne aerosols. Natural aerosols tend to be larger than human-made aerosols. These maps show when and where aerosols come from nature, humans, or both.
These maps depict how much hotter or cooler an ocean basin was compared to the long-term average. Temperature anomalies can indicate changes in ocean circulation or the arrival of patterns like El Niño and La Niña.
It measures about half the size of a football field and it is so small that you cannot see it on Google maps. This barren bit of rock off the coast of Canada has an unusual namesake: the Landsat 1 satellite. Hear about the discovery in the words of the woman who found it in satellite imagery.
Have you ever wondered what it would be like to live in a different part of the world? What would the weather be like? What kinds of animals would you see? Which plants live there? By investigating these questions, you are learning about biomes.
In honor of our 20th anniversary, we offer a selection of some of the most beautiful, newsworthy, interesting, and scientifically important images from the past 20 years — one for each day of the calendar year.
Snow and ice influence climate by reflecting sunlight back into space. When it melts, snow is a source of water for drinking and vegetation; too much snowmelt can lead to floods. These maps show average snow cover by month.