Editing Cosmic Background Explorer (section)

=== Intrinsic anisotropy of CMB ===
[[File:COBE DMR Image.PNG|thumb|upright=1.0|right|Data obtained at each of the three DMR frequencies — 31.5, 53, and 90 [[Hertz|GHz]] — following dipole subtraction.]]

The DMR was able to spend four years mapping the detectable anisotropy of cosmic background radiation as it was the only instrument not dependent on the dewar's supply of helium to keep it cooled. This operation was able to create full sky maps of the CMB by subtracting out galactic emissions and dipole at various frequencies. The cosmic microwave background fluctuations are extremely faint, only one part in 100,000 compared to the 2.73 K average temperature of the radiation field. The cosmic microwave background radiation is a remnant of the [[Big Bang]] and the fluctuations are the imprint of density contrast in the early universe. The density ripples are believed to have produced [[structure formation]] as observed in the universe today: clusters of galaxies and vast regions devoid of galaxies.<ref>{{Cite web |last=Dick |first=Steven J. |date=16 October 2006 |title=Voyages to the Beginning of Time |url=https://www.nasa.gov/exploration/whyweexplore/Why_We_24.html |access-date=2022-06-16 |website=nasa.gov |publisher=NASA |language=en |archive-date=16 June 2022 |archive-url=https://web.archive.org/web/20220616205611/https://www.nasa.gov/exploration/whyweexplore/Why_We_24.html |url-status=dead}} {{PD-notice}}</ref>