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In earliest image of cosmos, “strange” features

March 21, 2013
Courtesy of the Jet Propulsion Laboratory
and World Science staff

The most ac­cu­rate map ev­er made of the old­est light in the uni­verse is out—and it re­veals some “strange” fea­tures along with oth­er new in­forma­t­ion, as­tro­no­mers say.

The pic­ture comes from the Planck space mis­sion, a Eu­ro­pe­an Space Agen­cy proj­ect with NASA-contributed tech­nol­o­gy. The re­sults, sci­en­tists said, sug­gest the uni­verse is ex­pand­ing more slowly than had been thought, and that it’s 13.8 bil­lion years old, 100 mil­lion years old­er than pre­vi­ous es­ti­mates. 

A map of the oldest light in our universe, as detected 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. (Image credit: ESA and the Planck Collaboration)


The da­ta, they add, show there is less “dark en­er­gy” and more mat­ter, both nor­mal and “dark mat­ter,” in the uni­verse than pre­vi­ously known. 

Dark mat­ter is be­lieved to be an in­vis­i­ble sub­stance that can only be seen through the ef­fects of its gra­vity, while dark en­er­gy is push­ing our uni­verse apart. The na­ture of both re­mains mys­te­ri­ous.

“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.”

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 age, con­tents and oth­er fun­da­men­tal traits of our uni­verse are de­scribed in a sim­ple mod­el de­vel­oped by sci­en­tists, called the stand­ard mod­el of cos­mol­o­gy. The new da­ta are be­lieved to let sci­en­tists test and im­prove the mod­el with the great­est pre­ci­sion yet. 

Yet the map dis­plays some cu­ri­ous fea­tures 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 asym­met­ri­c 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.”

The find­ings al­so test the­o­ries de­scrib­ing infla­t­ion, a dra­mat­ic ex­pan­sion of the uni­verse that oc­curred im­me­di­ately af­ter its birth. In far less time than it takes to blink an eye, the uni­verse blew up by 100 tril­lion tril­lion times in size. The new map, by show­ing that mat­ter seems to be dis­trib­ut­ed ran­dom­ly, sug­gests that ran­dom pro­cesses were at play in the very early uni­verse on min­ute “quan­tum” scales, ac­cord­ing to sci­en­tists. This al­lows them to rule out many com­plex infla­t­ion the­o­ries in fa­vor of sim­ple ones.

“Pat­terns over huge patches of sky tell us about what was hap­pen­ing on the ti­ni­est of scales in the mo­ments just af­ter our uni­verse was born,” Law­rence said.

Planck 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. This rel­ic radia­t­ion pro­vides sci­en­tists with a snap­shot of the uni­verse 370,000 years af­ter the big bang. Light ex­isted be­fore this time, but it was locked in a hot “plas­ma” si­m­i­lar to a can­dle flame, which lat­er cooled and set the light free.

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


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The most accurate map ever made of the oldest light in the universe is out—and it reveals some “strange” features along with other new information, astronomers say. The picture comes from the Planck space mission, is a European Space Agency project with NASA-contributed technology. The results, scientists said, suggest the universe is expanding more slowly than scientists thought, and is 13.8 billion years old, 100 million years older than previous estimates. The data, they added, show there is less “dark energy” and more matter, both normal and “dark matter,” in the universe than previously known. Dark matter is an invisible substance that can only be seen through the effects of its gravity, while dark energy is pushing our universe apart. The nature of both remains mysterious. “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.” 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 age, contents and other fundamental traits of our universe are described in a simple model developed by scientists, called the standard model of cosmology. The new data are believed to let scientists test and improve the model with the greatest precision yet. Yet the map displays some curious features 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.” The findings also test theories describing inflation, a dramatic expansion of the universe that occurred immediately after its birth. In far less time than it takes to blink an eye, the universe blew up by 100 trillion trillion times in size. The new map, by showing that matter seems to be distributed randomly, suggests that random processes were at play in the very early universe on minute “quantum” scales, according to scientists. This allows them to rule out many complex inflation theories in favor of simple ones. “Patterns over huge patches of sky tell us about what was happening on the tiniest of scales in the moments just after our universe was born,” Lawrence said. Planck 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. This relic radiation provides scientists with a snapshot of the universe 370,000 years after the big bang. Light existed before this time, but it was locked in a hot plasma similar to a candle flame, which later cooled and set the light free. 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. Scientists believe these imprints, appearing as splotches in the Planck map, are the seeds from which matter grew, forming stars and galaxies.