Riders on the Earth Together

On the Cover: When seen from space, Earth—with its ultramarine oceans, green and tan land masses, and swirling white clouds—looks like no other planet in our solar system. This spectacular image of our "blue marble" is the most detailed true-color image of Earth to date. Using a collection of satellite-based observations, scientists stitched together months of data on the land, oceans, sea ice, clouds, and even city lights into a seamless true-color mosaic of every square kilometer of our planet. This portrait of Earth's Western Hemisphere shows North America, Central America, and the top of South America.