COBE
Overview
A portion of the COBE all-sky image from 1992 showing the CMB. Red areas are slightly warmer than average and blue areas are slightly cooler than average. The lines of latitude and longitude are, unfortunately, baked into the image.
Note
See this section’s top page for an introduction on the cosmic microwave background.
In 1989, the Cosmic Background Explorer (COBE) was launched into orbit to see, once and for all, whether the CMB was a blackbody and to see a more detailed version of the temperature fluctuations that belie the early structure of the universe.
COBE’s Differential Microwave Radiometer observed light in the range from a few millimeters to about 1 cm in wavelength. The results were indisputable. COBE had confirmed decades of theories and conflicting experiments with observational proof that the CMB was indeed the light left over from a Big Bang.
COBE also confirmed that the light was remarkably uniform. No matter where the telescope looked, it observed radiation equivalent to a 2.73-Kelvin blackbody with deviations on the order of one part in 100,000. These slight differences in temperature correspond to the density structure of the universe at this time, 380,000 years after the Big Bang. These fluctuations in density are the seeds of the large-scale structure we see today.
In the image, the red areas are relatively hotter areas of the CMB, while the blue areas are cooler than the average. The lines of latitude and longitude are baked into this image, and reflect galactic coordinates.
While the COBE map yielded the first all-sky image of the CMB, and netted two of its principle scientists the Nobel Prize, it was superseded by more accurate maps in the coming years, namely the WMAP and Planck missions.
Profiles
Dossier
Census: |
1 all-sky image |
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Asset File: |
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OpenSpace Version: |
2 |
Reference: |
Structure in the COBE Differential Microwave Radiometer First-Year Maps |
Prepared by: |
Brian Abbott (AMNH) |
Source Version: |
2.02 |
License: |