WMAP Google Earth Microwave Sky Images
Five Year Maps

This page provides access to a number of WMAP images that have been formatted to be compatible with the Google Earth 3D imaging tool. Prior to using these files, you will need to download and install Google Earth as a separate application on your computer. You may configure your browser to launch Google Earth when a .kmz file is encountered; clicking on the images below will then automatically load them into the application. These images are provided as a courtesy to our users; they do not constitute an endorsement of any product or service.

The Cosmic Microwave Background (CMB) radiation is the remnant heat from the Big Bang. This radiation pervades the universe and, if we could see in microwaves, it would appear as a nearly uniform glow across the entire sky. However, when we measure this radiation very carefully we can discern extremely faint variations in the brightness from point to point across the sky, called "anisotropy". These variations encode a great deal of information about the properties of our universe, such as its age and content. The "Wilkinson Microwave Anisotropy Probe" (WMAP) mission has measured these variations and found that the universe is 13.7 billion years old, and it consists of 5% atoms, 23% dark matter, and 72% dark energy.

Click on the images below to retrieve the Google Sky files. The file wmap_google.zip (80 MB) contains all these files for those that would like to have a local copy for improved browser performance; when using these images, select the File->Open command in the Google Earth application and simply navigate to these files.

Image Credit: NASA / LAMBDA Archive Team

WMAP Five Year CMB Map

(6420 kB)
The first image shows the CMB fluctuations from the Five Year WMAP survey. The average brightness corresponds to a temperature of 2.725 Kelvins (degrees above absolute zero; equivalent to -270 C or -455 F). The colors represent temperature variations, as in a weather map: red regions are warmer and blue regions are colder than average by 0.0002 degrees. This map was formed from the five frequency bands shown below in such a way as to suppress the signal from our own Milky Way Galaxy.
WMAP Five Year Frequency Band Maps (Linear Color Scale)
K Band -- 23 GHz 4840 kB	Ka Band -- 33 GHz 7365 kB	Q Band -- 41 GHz 8212 kB	V Band -- 61 GHz 9132 kB	W Band -- 94 GHz 9092 kB
In addition to the CMB, our own Milky Way Galaxy is a source of microwave radiation. Fortunately, the two sources have a different frequency spectrum (or "color"), so they can be separated using multifrequency observations. WMAP uses 5 frequency bands to discern CMB emission from Galactic emission: 23, 33, 41, 61, and 94 GHz. These five images show the microwave brightness measured in each frequency band. The signal is measured in units of Kelvins, and the color scale goes from blue at -0.0002 Kelvins below average (-200 microKelvins) to red at 0.0002 Kelvins above average (+200 microKelvins). The red band running through the center of the image is the emission from our Milky Way, which is much brighter than the CMB signal. By combining these five images in a particular way (as shown in the Internal Linear Combination Map), we can suppress the signal from the Milky Way.
WMAP Five Year Frequency Band Maps (Nonlinear Color Scale)
K Band -- 23 GHz 5900 kB	Ka Band -- 33 GHz 6956 kB	Q Band -- 41 GHz 7412 kB	V Band -- 61 GHz 8204 kB	W Band -- 94 GHz 8520 kB
These are the same five images as above, except the color scale is distorted to show both the faint variations in the CMB and the much brighter variations in the Milky Way signal.

Projection Conventions

Google Earth places the observer at the center of a sphere looking out at the sky.

The images projected here are in celestial coordinates (right ascension (RA) and declination (Dec)), with the center representing zero degrees RA and Dec. The entire top of the image corresponds to 90 degrees Dec and the entire bottom corresponds to -90 degrees Dec. This orientation was chosen to allow Google Earth to correctly position star and constellation overlays on top of the image.

Also available:

• Google Earth, Seven Year WMAP Data Release
• Microwave Sky Images Formatted for Microsoft's Worldwide Telescope
• Microwave Sky Images Formatted for Science on the Sphere