Best maps of the universe, bugs and all

Maps from the European Space Agency’s Planck satellite reveal the cosmos in a range of microwave and infrared frequencies.

Planck’s primary mission was to precisely measure the cosmic microwave background, or CMB, which is 13.8-billion-year-old radiation that allows astronomers to probe the universe’s first moments (SN: 12/28/13, p. 21). The CMB appears as speckles; blue regions are slightly colder than the average CMB temperature of 2.7 kelvins, while orange ones are warmer.

To study these tiny fluctuations, scientists must filter out galactic radiation emitted by speedy electrons (red at lower frequencies) and dust grains (red and white at higher frequencies).

“From the standpoint of the CMB, all this foreground stuff is like bugs on a windshield,” says Planck project scientist Charles Lawrence. “But entomology is an interesting subject.”

The maps will help astronomers learn more about the Milky Way, as well as the history of the cosmos.