The European satellite Planck has completed its first All-Sky Survey
High resolution mapping of the first light in the Universe
The Planck satellite must survey the entire sky to construct a high resolution image of the Universe's fossil radiation. The satellite is turning on its axis with a speed of rotation of one turn per minute, around an axis offset by 85° in such a way as to sweep out a small strip of the sky on each rotation. As the satellite follows the movement of the sun, this strip is offset by 1° per day. Planck therefore takes six months to survey the entire sky. Since its minimum lifespan is 15 months, it will therefore survey the entire sky at least twice. Video credits: ESA (animation by C. Carreau). Read more......