Planck and the Cosmic microwave background
![](https://cdn.sci.esa.int/documents/34222/35279/1567217355992-Planck_and_the_Cosmic_microwave_background_625.jpg)
Date: 20 March 2013
Satellite: Planck
Copyright: ESA and the Planck Collaboration - D. Ducros
The anisotropies of the Cosmic microwave background (CMB) as observed by Planck. The CMB is a snapshot of the oldest light in our Universe, imprinted on the sky when the Universe was just 380 000 years old. It shows tiny temperature fluctuations that correspond to regions of slightly different densities, representing the seeds of all future structure: the stars and galaxies of today.
Last Update: 1 September 2019