Planck’s New Recipe of the Universe: More Matter, Less Dark Energy

By Breanna Draxler | March 21, 2013 11:40 am

This map shows the oldest light in our universe, as detected with the greatest precision yet by the Planck mission. The ancient light, called the cosmic microwave background, was imprinted on the sky when the universe was 370,000 years old. It shows tiny temperature fluctuations that correspond to regions of slightly different densities, representing the seeds of all future structure: the stars and galaxies of today. By analyzing the light patterns in this map, scientists are fine-tuning what we know about the universe, including its origins, fate and basic components. Image courtesy of ESA and the Planck Collaboration

Today NASA released a new map of the universe, and described it with a slew of superlatives: It is the “most accurate,” “most detailed,” “best map ever.” It’s that good.

Based on the first 15 months of data from the Planck mission’s all-sky observations, this new map shakes up scientists’ understanding of the standard model of cosmology, including how old the universe is, what it’s made of, and how it came to be.

The data suggests that the universe’s age ticker is currently at 13.8 billion years, some 100 million years older than previous estimates. Planck also overrode existing estimates of Hubble’s constant—the universe’s expansion rate—saying it’s close to 67.15 kilometers/second/megaparsec—slightly slower than we’d previously thought.

Planck’s preliminary results also suggests that the mix of the universe’s constituent parts contains less energy and more matter. The revised numbers show a 4 percent drop in the amount of dark energy in the universe. The difference is made up in a 10 percent increase in dark matter (now 26.8 percent of the universe) and 6 percent more normal matter (now 4.9 percent of the universe). The mission found that this matter is also distributed randomly throughout the universe, rather than evenly, which helps scientists simplify their theory of inflation in the universe’s early days. Such advances may bring scientists closer to comprehending the universe’s oh-so-elusive dark matter.

By measuring variations in cosmic microwave background patterns with more sensitivity and at a higher resolution, the Planck mission enabled scientists from Europe, the U.S. and Canada to create a far more accurate and detailed map than those of previous missions like NASA’s Cosmic Background Explorer (COBE) or the Wilkinson Microwave Anisotropy Probe (WMAP). But WMAP’s results, released earlier this year, were based on nine years of data, while the Planck map only shows results from the first 15 months of its mission. Planck has been churning out data from its all-sky observations since it was launched in 2009, but full results won’t be available until 2014.

The first spacecraft, launched in 1989, is NASA’s Cosmic Background Explorer, or COBE (left), which demonstrated that tiny variations in the ancient light reveal information about the state of the universe. These variations, called anistotropies, came into sharper focus with NASA’s next-generation spacecraft, the Wilkinson Microwave Anisotropy Probe, or WMAP (middle). This mission, launched in 2001, found strong evidence for inflation, the very early epoch in our universe when it expanded dramatically in size, and measured basic traits of our universe better than ever before. The most advanced satellite yet of this type is Planck, a European Space Agency mission with significant NASA contributions. Planck, launched in 2009, images the sky with more than 2.5 times greater resolution than WMAP, revealing patterns in the ancient cosmic light as small as one-twelfth of a degree on the sky. 
Image credit: NASA/JPL-Caltech/ESA

CATEGORIZED UNDER: Space & Physics, top posts

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