Planck space observatory, with the Earth in the background, artwork. This unmanned spacecraft was launched from Earth on 14 May 2009. It then began travelling to the second Lagrangian point (L2), situated about 1.5 million kilometres from Earth in the direction opposite to the Sun. The aim of the mission is to study the Cosmic Microwave Background, the radiation left over from the Big Bang. Planck took around 6 months to arrive, and then spent 15 months surveying the sky. Following excellent initial results, the mission was extended, with observations continuing to the end of 2011. The final results are expected at the end of 2012.
