Below is a false-colour image of the whole sky as seen by Planck. The dust throughout the Galaxy is shown in blue, while hot gas can be seen as red regions across the centre of the image. In the background, the mottled yellow features are relic radiation, called the Cosmic Microwave Background, which contains information about the earliest stages of the Universe. This image is a low-resolution version of the full data set. Image credit: ESA / LFI and HFI Consortia.