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Death by helium for cosmos-mapping Planck observatory

The last of the spacecraft tasked with measuring the big bang's echo has run out of liquid coolant, effectively ending the mission

Artist's impression of Planck (Image: ESA 2002. Illustration by Medialab)
Artist鈥檚 impression of Planck (Image: ESA 2002. Illustration by Medialab)
Perseus, as seen by Planck (Image: ESA/LFI and HFI Consortia)
Perseus, as seen by Planck (Image: ESA/LFI and HFI Consortia)

One of astronomy鈥檚 great orbiting observatories has breathed its last. On 14 January, the liquid helium cooling one of the two photon sensors onboard the ran dry, ending a mission to map the big bang鈥檚 echo.

The European Space Agency telescope has been measuring the cosmic microwave background (CMB) with unprecedented accuracy since 2009.

The helium was due to run out when it did. 鈥淭he supplies lasted almost until the day we predicted when it first launched,鈥 says of the European Space Research and Technology Centre in Noordwick, the Netherlands. He plans to operate the telescope鈥檚 uncooled sensor for a further year to calibrate the observatory but the mission is effectively over.

Planck鈥檚 data will help tease apart the large-scale structure of the universe and determine how it formed. It will also provide the most detailed views of nearer phenomenon, such as galactic dust and magnetic fields, which are superimposed on the spacecraft鈥檚 view of the CMB. This data will be released in early 2013, once it has been processed.

Planck is the last in a line of observatories studying the CMB, which date back to 1989. As yet, there is no successor. 鈥淲e want to know what the spacecraft will reveal before planning the next mission,鈥 says Tauber.

Topics: Cosmology