A perfect sky

25 June 2013 - ESA astronaut Luca Parmitano is spending six months on the International Space Station conducting experiments and keeping the orbital outpost running with five colleague astronauts. In Luca's spare time he photographs our world from 400 km high, looking out of the Station's panoramic Cupola. Luca tweeted the picture above with the comment: "The sky is simply perfect." Of course, for people living down below, the weather would have been described as "patchy, with sunlight coming through at times". Orbiting at 28 800 km/h, Luca is privileged to see our planet from a unique perspective. Here, Earth's curvature is clearly visible, with the thin layer of pale blue atmosphere separating us from the harshness of space. Our atmosphere not only provides the air we breathe but also protects us from the Sun's radiation. Luca does not have much time to ponder the beauty and fragility of our planet - he has a busy schedule.