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WMAP

WMAP Google Earth Microwave Sky Images

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 4.6% 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.

WMAP 5-Year CMB Map

WMAP ILC Map
(6420 kB)

The first image shows the CMB fluctuations from the 5-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 5-Year Frequency Band Maps (Linear Color Scale)

WMAP K Band Map
K Band -- 23 GHz
4840 kB
WMAP Ka Band Map
Ka Band -- 33 GHz
7365 kB
WMAP Q Band Map
Q Band -- 41 GHz
8212 kB
WMAP V Band Map
V Band -- 61 GHz
9132 kB
WMAP W Band Map
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 (shown above), we can suppress the signal from the Milky Way.

WMAP 5-Year Frequency Band Maps (Nonlinear Color Scale)

WMAP K Band Map
K Band -- 23 GHz
5900 kB
WMAP Ka Band Map
Ka Band -- 33 GHz
6956 kB
WMAP Q Band Map
Q Band -- 41 GHz
7412 kB
WMAP V Band Map
V Band -- 61 GHz
8204 kB
WMAP W Band Map
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.

Also available:

A service of the HEASARC and of the Astrophysics Science Division at NASA/GSFC
Goddard Space Flight Center, National Aeronautics and Space Administration
HEASARC Director: Dr. Alan P. Smale
LAMBDA Director: Dr. Eric R. Switzer
NASA Official: Dr. Eric R. Switzer
Web Curator: Mr. Michael R. Greason