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.
Chlorophyll is used by algae and other phytoplankton--the grass of the sea--to convert sunlight and carbon dioxide into sugars. These maps show chlorophyll concentrations in the ocean, revealing where phytoplankton are thriving.
To celebrate EO's 20th anniversary and the 50th anniversary of Earth Day, we want you to pick our all-time best image. Each week from March 23 to April 28, you can vote for your favorites, narrowing the field from 32 nominees down to one champion.
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.
Airborne aerosols can cause or prevent cloud formation and harm human health. These maps depict aerosol concentrations in the air based on how the tiny particles reflect or absorb visible and infrared light.
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.
Whether started by humans (farming, logging, or accidents) or by nature (lightning), fires are always burning somewhere on Earth. These maps show the locations of fires burning around the world each month.
Find out about sea ice and its effects on ecosystems and global climate by looking at how and when it forms on Earth. Plus, learn how different types of water freeze in our “DIY Science” activity: “Saltwater is Cool (Literally).”
These maps show the ‘metabolism” of Earth’s plants and trees. Net primary productivity is the difference between the amount of carbon dioxide absorbed during photosynthesis minus the amount released by respiration.
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.
Since its launch on the web in April 1999, NASA Earth Observatory has published more than 15,500 image-driven stories about our planet. In celebration of our 20th anniversary -- as well as the 50th anniversary of Earth Day -- we want you to help us choose our all-time best image.