The mission of the Plank space observatory included a number of fascinating goals, such as measuring the amount of dark matter in the universe, testing theories of inflation, studying the origins of the universe, and examining the material composition of other galaxies. In short, Planck used highly sensitive instruments to observe the cosmic microwave background, which "preserves a picture of the Universe as it was about 380,000 years after the Big Bang, and can reveal the initial conditions for the evolution of the Universe." Readers can find much to explore on this page of the European Space Agency website, including excellent information in the About Planck tab. The Microwave Universe, The Spacecraft, The Mission, and a host of amazing images and videos housed under the Multimedia tab round out the site.