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Planck Reveals Most Detailed Map Yet Of The Milky Way's Magnetic Field

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Justine Alford

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861 Planck Reveals Most Detailed Map Yet Of The Milky Way's Magnetic Field
ESA and the Planck Collaboration. The magnetic field of our Milky Way Galaxy as seen by ESA’s Planck satellite.

In a collaborative effort, astrophysicists have used data collected from the Planck Space Telescope to generate the most detailed map of our galaxy’s magnetic field yet, which could further our knowledge of the very early universe. The team that produced the map includes scientists from the University of British Columbia and the Canadian Institute for Astrophysics (CITA) at the University of Toronto. The results are described in four forthcoming papers within the journal Astronomy and Astrophysics.

Since its discovery in 1964, scientists have been measuring the Cosmic Microwave Background (CMB) in order to find out more about the birth and evolution of the universe. The CMB is the afterglow of the Big Bang and dates from around 380,000 years after this event. The European Space Agency's Planck Space Telescope, which was launched in 2009, has given us the most comprehensive picture of the CMB yet, but that’s not all it can be used for.


Planck is able to pick up light from tiny dust particles within our galaxy and can determine the directionality of the vibrations of these light waves, which is called polarization. This information can then be used to deduce the orientation of the magnetic field lines.

According to Douglas Scott, an astrophysicist at the University of British Columbia, the magnetic field of the Milky Way is important for investigating the many phenomena within it. “Planck has given us the most detailed picture of it yet,” he says.

“Dust is often overlooked but it contains the stuff from which terrestrial planets and life form,” said Professor Peter Martin, CITA, who studies dust in the Milky Way. “So by probing the dust, Planck helps us understand the complex history of the galaxy as well as the life within it.”

Planck data to be released later this year will help scientists confidently distinguish signal from the Milky Way from the polarized CMB signal, which will be very handy for those investigating the birth and evolution of the universe. It should also further our knowledge of the universe from as early as one second after the Big Bang to the time when the first stars were being born.


“These results help us lift the veil of emissions from these tiny but pervasive Galactic dust grains which obscure a Planck goal of peering into the earliest moments of the Big Bang to find evidence for gravitational waves created in that epoch,” says CITA Professor J. Richard Bond


spaceSpace and Physics
  • tag
  • Milky Way,

  • cosmic microwave background,

  • big bang,

  • Planck Space Telescope,

  • Planck,

  • CMB