Science Magazine

Universe Older and Slower Than Previously Thought

Posted on the 22 March 2013 by Ningauble @AliAksoz

Europe’s Planck spacecraft obtained and brought some pretty interesting data for us. The most accurate and detailed map ever made of the oldest light in the universe.

Planck was launched in 2009 and has been scanning the skies ever since, mapping the cosmic microwave background, the afterglow of the theorized big bang that created our universe. It is a European Space Agency mission. NASA contributed mission-enabling technology and U.S., European and Canadian scientists work together to analyze the Planck data.




Image credit: ESA and the Planck Collaboration.


The map results suggest the universe is 13.8 billion years old, 100 million years older than previous estimates and is expanding more slowly than we thought. The data also show there is less dark energy and more matter in the universe than previously known.

“Astronomers worldwide have been on the edge of their seats waiting for this map,” said Joan Centrella, Planck program scientist at NASA Headquarters in Washington. “These measurements are profoundly important to many areas of science, as well as future space missions. We are so pleased to have worked with the European Space Agency on such a historic endeavor.”

The map, based on the mission’s first 15.5 months of all-sky observations, reveals tiny temperature fluctuations in the cosmic microwave background, ancient light that has traveled for billions of years from the very early universe to reach us. The patterns of light represent the seeds of galaxies and clusters of galaxies we see around us today.

“As that ancient light travels to us, matter acts like an obstacle course getting in its way and changing the patterns slightly,” said Charles Lawrence, the U.S. project scientist for Planck at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “The Planck map reveals not only the very young universe, but also matter, including dark matter, everywhere in the universe.”

The newly estimated expansion rate of the universe, known as Hubble’s constant, is 67.15 plus or minus 1.2 kilometers/second/megaparsec. A megaparsec is roughly 3 million light-years. The new estimate of dark matter content in the universe came up from 24 percent to %26.8, while dark energy falls to %68.3 from 71.4 percent. Normal matter now is %4.9, up from %4.6.

The cosmic microwave background is remarkably uniform over the entire sky, but tiny variations reveal the imprints of sound waves triggered by quantum fluctuations in the universe just moments after it was born. These imprints, appearing as splotches in the Planck map, are the seeds from which matter grew, forming stars and galaxies.

The age, contents and other fundamental traits of our universe are described in the so-called “Standard Model” of cosmology, which has been developed over the years by astronomers. These new data have allowed researchers to test and improve the Standard Model with the greatest precision yet. At the same time, some curious features are observed that don’t quite fit with the simple picture. For example, the model assumes the sky is the same everywhere, but the light patterns are asymmetrical on two halves of the sky, and there is a spot extending over a patch of sky that is larger than expected.

“On one hand, we have a simple model that fits our observations extremely well, but on the other hand, we see some strange features which force us to rethink some of our basic assumptions,” said Jan Tauber, the European Space Agency’s Planck project scientist based in the Netherlands. “This is the beginning of a new journey, and we expect our continued analysis of Planck data will help shed light on this conundrum.”

Complete results from Planck, which still is looking out there, will be released in 2014.




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