Operating between 2009 and 2013, ESA’s Planck mission scanned the sky at microwave wavelengths to observe the cosmic microwave background, or CMB, which is the most ancient light emitted in the history of our Universe. Data from Planck have revealed an ‘almost perfect Universe’: the standard model description of a cosmos containing ordinary matter, cold dark matter and dark energy, populated by structures that had been seeded during an early phase of inflationary expansion, is largely correct, but a few details to puzzle over remain. In other words: the best of both worlds.