The Planck deep space telescope is off to a warm retirement. After a four-year mission that revealed the universe is 80 million years older than scientists estimated, Planck is headed to a permanent parking spot orbiting the sun. Rest well, little traveller.
Launched in 2009, the 4.2m Planck recorded the Cosmic Microwave Background, the oldest photons in the universe formed just after the Big Bang. To detect temperature variations as small as a few millionths of a degree, Planck used a 4.2m detector cooled to near absolute zero. Alongside its sister telescope, the infrared-detecting Herschel Space Observatory, Planck gave scientists a better understanding of the proportions of ingredients that make up our universe.
Herschel went offline in April of this year, but Planck soldiered on until this month, when its liquid helium coolant ran out. Scientists sent the final command today. But while Planck is leaving Earth behind on its way to orbit the sun, the data it generated will be pored over by scientists for years to come; the next data set will be released in 2014. [ESA, PhysOrg, PopSci, NASA]