Planck Observatory Looks Back in Time

March 21, 2013

Back in 2009, I posted a couple of notes here about the European Space Agency’s [ESA] Planck Observatory, The observatory operates in the microwave part of the electromagnetic spectrum, and is intended to make the most precise measurements yet of the Cosmic Microwave Background, a faint remaining echo of the aftermath of the Big Bang.  At the time I wrote, the spacecraft had just gotten ready to work, having reached its normal operating temperature of 0.1° K (-273.05° Celsius), just above absolute zero (0°K).

According to an article at the BBC News site, the Planck has now completed a 15-month sky survey, and the ESA has released a map of the results.

A spectacular new map of the “oldest light” in the sky has just been released by the European Space Agency.

Scientists say its mottled pattern is an exquisite confirmation of our Big-Bang model for the origin and evolution of the Universe.

Although the data broadly confirm the “Big Bang” model for the formation of the Universe, they do suggest some refinements from previous knowledge.  The Universe appears to be slightly older, at 13.82 billion years, that previously thought, by about 50 million years.  This indicates a slightly slower rate of expansion than previously calculated.  The breakdown of the Universe’s composition also works out a bit differently,   Based on the Planck results, there is a bit more matter (both ordinary and dark matter) than previous.y thought, and a little less dark energy.   The comparative figures are:

Component Previous Post Planck
Normal Matter 4.5 % 4.9 %
Dark Matter 22.7 26.8
Dark Energy 72.8 68.3

The Planck data have also confirmed some small anomalies that were previously noted in the data from NASA’s Williamson Microwave Anisotropy Probe (WMAP).  According to the theory, the differences in the level of background radiation (represented by the color “mottling” of the map) correspond to differences in the density of matter in the early Universe.

Cosmic Microwave Background

Cosmic Microwave Background (from Planck)
Image: ESA/Planck Collaboration

In the CMB map, above, the lower half of the image seems to be slightly warmer (orange / red) than the upper half; there also seems to be a cool spot (blue) just below and to the right of the center.  The reason for these anomalies is not known; they may hint at some new refinements to the underlying physics, or perhaps result from another, unknown microwave source.  Taken as a whole, though, the data seem to support the current models of the development and expansion of the early Universe.

Ars Technica also has an article on these results.

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