NASA Picture: Blue Marble: Next Generation
Note: The image [link supplied below] is very large: 21600 x 10800 pixels [2 km per pixel] and 113 MB.
Link: Blue Marble: Next Generation
Information from NASA about Blue Marble: Next Generation:
Blue Marble: Next Generation improves the techniques for turning satellite data into digital images. Among the key improvements is greater detail in areas that usually appear very dark to the satellite (because a large amount of sunlight is being absorbed), for example in dense tropical forests. The ability to create a digital image that provides great detail in darker regions without 'washing out' brighter regions, like glaciers, snow-covered areas, and deserts is one of the great challenges of visualizing satellite data. The new version also improves image clarity, and gives highly reflective bodies of water, such as salt lakes, a more realistic appearance.
Those who intend to use the Blue Marble: Next Generation in their own publications or projects should be aware of areas that still require improvement. Areas of open water still show some 'noise.' In tropical lowlands, cloud cover during the rainy season can be so extensive that obtaining a cloud-free view of every pixel of the area for a given month may not be possible. Deep oceans are not included in the source data; the creator of the Blue Marble uses a uniform blue color for deep ocean regions, and this value has not been completely blended with observations of shallow water in coastal areas. The lack of blending may, in some cases, make the transition between shallow coastal water and deep ocean appear unnatural. Finally, the data do not completely distinguish between snow and cloud cover in areas with short-term snow cover (less than three or four months). This problem may be resolved in the future through the use of a more sophisticated snow mask.
Blue Marble: Arctic Edition