Planck’s whole sky


Pick of the pics

Planck’s first overview of the cosmos

Credit: ESA / LFI and HFI Consortia

Microwaves from the entire sky, surveyed by Europe’s Planck spacecraft since August 2009, are here mapped in galactic coordinates. The centre of the Milky Way Galaxy, in Sagittarius, is in the middle. The ribbon of the Milky Way (the flat disc of the Galaxy) extends horizontally across the map, with Cygnus conspicuous towards the left and Orion towards the right. Streamers above and below the disc are regions of star formation. The more subtle mottled regions top and bottom show the cosmic microwave background, from the formation of the first atoms 400,000 years after the Big Bang. The strong microwaves from the Galaxy will have to be gauged and subtracted to reveal hidden parts of that background. Crucial for making the distinction is Planck’s range of nine different microwave frequencies, 30 to 850 Ghz, and its ability to measure the temperature of the sky to one-sixth of a degree.

In Magic Universe I call it “looking for the pattern on the cosmic wallpaper”. Named after the quantum theory pioneer, Planck is the successor to NASA’s WMAP mission. In 2003 WMAP returned wonderful information about the cosmic microwave background but did not quite pin down the theory of the Big Bang that best fits the facts. Maybe Planck will do that, and there seems little point in updating Magic Universe about the cosmic wallpaper until the full Planck results are in, after four surveys of the whole sky, in 2012.

George Efstathiou of Cambridge, the Planck Survey Scientist, says “It has taken sixteen years of hard work by many scientists in Europe, the USA and Canada, to produce this new image of the early Universe. Planck is working brilliantly and we expect to learn a lot about the Big Bang and the creation of our Universe.”

Reference for Efstathiou quote: UK Space Agency press release 5 July 2010.