Planck Takes Magnetic Fingerprint of Our Galaxy

JPL/NASA | MAY 8, 2014

A new image from the Planck space telescope reveals the magnetic field lines of our Milky Way galaxy. The fingerprint-like map allows astronomers to study the structure of the magnetic field and better understand the process of star formation.

The magnetic field of our Milky Way galaxy. Image Credit: ESA and the Planck Collaboration.

Planck is a European Space Agency mission with significant NASA contributions. Though the mission stopped collecting data in 2013, scientists are still analyzing its huge data sets for more clues to the history of our universe.

In particular, they are looking at polarized light, both from the early universe and from dust in our galaxy as shown in the new map.

Light can be described as a wave of electric and magnetic fields that vibrate in directions at right angles to each other and to their direction of travel. Usually, these fields can vibrate at all orientations. However, if they happen to vibrate preferentially in certain directions, the light is "polarized."

This can happen, for example, when light bounces off a reflective surface like a mirror or the sea. Special filters can be used to absorb this polarized light, which is how polarized sunglasses eliminate glare.

In space, the light emitted by stars, gas and dust can also be polarized in various ways that depend on magnetic fields. Consequently, the swirls, loops and arcs in this new image trace the structure of the magnetic field in our home galaxy.

Darker regions correspond to stronger polarized emission, and the striations indicate the direction of the magnetic field projected on the plane of the sky. The Planck image shows that there is large-scale organization in some parts of the galactic magnetic field.

The dark band running horizontally across the center corresponds to the galactic plane. The data also reveal variations of the polarization direction within nearby clouds of gas and dust. This can be seen in the tangled features above and below the plane, where the local magnetic field is particularly disorganized.

YOU MAY ALSO LIKE

NASA Mars weathercam helps find big new crater

Researchers have discovered on the Red Planet the largest fresh meteor-impact crater ever firmly documented with before-and-after images.

Hubble Sees Neptune's Mysterious Shrinking Storm

Three billion miles away on the farthest known major planet in our solar system, an ominous, dark storm – once big enough to stretch across the Atlantic Ocean from Boston to Portugal – is shrinking out of existence as seen in pictures of Neptune taken by NASA’s Hubble Space Telescope.

Astronomers confounded by massive rocky world

Astronomers have discovered a rocky planet that weighs 17 times as much as Earth and is more than twice as large in size. This discovery has planet formation theorists challenged to explain how such a world could have formed.

Mercury passes in front of the Sun, as seen from Mars

NASA's Curiosity Mars rover has imaged the planet Mercury passing in front of the sun, visible as a faint darkening that moves across the face of the sun.

ALMA Finds Ingredient of Life Around Infant Sun-like Stars

ALMA has observed stars like the Sun at a very early stage in their formation and found traces of methyl isocyanate — a chemical building block of life.

NASA Shows New Tongan Island Made of Tuff Stuff, Likely to Persist Years

In late December 2014, a submarine volcano in the South Pacific Kingdom of Tonga erupted, sending a violent stream of steam, ash and rock into the air. The ash plumes rose as high as 30,000 feet (9 kilometers) into the sky, diverting flights.