LOOKING BACK THE SKY AT NIGHT
March 1993
On 7 March 1993, the team on
The Sky at Night looked at the recent results of the Cosmic Background Explorer (COBE).
Launched in 1989, COBE spent four years scanning the sky at microwave and infrared wavelengths. It was able to create the most precise map, up to that point, of the cosmic microwave background radiation (CMB). This is the first light of the Universe from when it started to glow 400,000 years after the Big Bang. Over time the once visible light has been stretched out, or redshifted, so that now it has a longer microwave wavelength.
As the structure of the Universe at the time the background was created is imprinted on the CMB, by studying it researchers can see what the Universe was like at these early times. The findings made using COBE’s data provided the most compelling proof yet that the Big Bang theory was correct.