Planck satellite: Maps detail Universe's ancient light

A map tracing the "oldest light" in the sky has been produced by Europe's Planck Surveyor satellite. Its pattern confirms the Big Bang theory for the origin of the Universe but subtle, unexpected details will require scientists to adjust some of their ideas.

Map of the oldest light in the Universe.

The map shows tiny deviations from the average background temperature, where blue is slightly cooler and red is slightly warmer. The cold spots are where matter was more concentrated and later collapsed under gravity to form stars and galaxies. Image: ESA/Planck Collaboration


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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.

But there are features in the picture, they add, that are unexpected and will require ideas to be refined.

The map was assembled from 15 months' worth of data acquired by the 600m-euro (£515m) Planck space telescope.

It details what is known as the cosmic microwave background, or CMB - a faint glow of long wavelength radiation that pervades all of space.

Its precise configuration, visible in the new Planck data, is suggestive of a cosmos that is slightly older than previously thought - one that came into existence 13.82 billion years ago.

This is an increase of about 50 million years on earlier calculations.

The map's pattern also indicates a subtle adjustment is needed to the Universe's inventory of contents.

It seems there is slightly more matter out there (31.7%) and slightly less "dark energy" (68.3%), the mysterious component thought to be driving the cosmos apart at an accelerating rate.

"I would imagine for [most people] it might look like a dirty rugby ball or a piece of modern art," said Cambridge University's George Efstathiou, presenting the new picture here at Esa headquarters in Paris.

"But I can assure you there are cosmologists who would have hacked our computers or maybe even given up their children to get hold of this map, we're so excited by it."

Planck is the third western satellite to study the CMB. The two previous efforts - COBE and WMAP - were led by the US space agency (Nasa). The Soviets also had an experiment in space in the 1980s that they called Relikt-1.

How Planck's view hints at new physics

Planck anomalies graphic
  • The CMB's temperature fluctuations are put through a number of statistical analyses
  • Deviations can be studied as a function of their size on the sky - their angular scale
  • When compared to best-fit Big Bang models, some anomalies are evident
  • One shows the fluctuations on the biggest scales to be weaker than expected
  • Theorists will need to adjust their ideas to account for these features

The CMB is the light that was finally allowed to spread out across space once the Universe had cooled sufficiently to permit the formation of hydrogen atoms - about 380,000 years into the life of the cosmos.

It still bathes the Earth in a near-uniform glow at microwave frequencies, and has a temperature profile that is just 2.7 degrees above absolute zero.

But it is possible to detect minute deviations in this signal, and these fluctuations - seen as mottling in the map - are understood to reflect the differences in the density of matter when the light parted company and set out on its journey all those years ago.

The fluctuations can be thought of as the seeds for all the structure that later developed in the cosmos - all the stars and galaxies.

Scientists subject the temperature deviations to a range of statistical analyses, which can then be matched against theoretical expectations.

This allows them to rule in some models to explain the origin and evolution of the cosmos, while ruling out a host of others.

The team that has done this for Planck's data says the map is an elegant fit for the standard model of cosmology - the idea that the Universe started in a hot, dense state in an incredibly small space, and then expanded and cooled.

At a fundamental level, it also supports an "add-on" to this Big Bang theory known as inflation, which postulates that in the very first moments of its existence the Universe opened up in an exponential manner - faster than light itself.

But because Planck's map is so much more detailed than anything previously obtained, it is also possible to see some anomalies in it.

Temperature anomalies in Planck data Planck has confirmed the north/south differences and a "cold spot" in the data

One is the finding that the temperature fluctuations, when viewed across the biggest scales, do not match those predicted by the standard model. Their signal is a bit weaker than expected.

Planck's new numbers

  • 4.9% normal matter - atoms, the stuff from which we are all made
  • 26.8% dark matter - the unseen material holding galaxies together
  • 68.3% dark energy - the mysterious component accelerating cosmic expansion
  • The number for dark energy is lower than previously estimated
  • The new age - 13.82 billion years - results from a slower expansion
  • This is described by a value known as the Hubble Constant
  • It too is revised to 67.15 km per second, per megaparsec (3.2 million light-years)

There appears also to be an asymmetry in the average temperatures across the sky; the southern hemisphere is slightly warmer than the north.

A third anomaly is a cold spot in the map, centred on the constellation Eridanus, which is much bigger than would be predicted.

These features have been hinted at before by Planck's most recent predecessor - Nasa's WMAP satellite - but are now seen with greater clarity and their significance cemented.

A consequence will be the binning of many ideas for how inflation propagated, as the process was first introduced in the 1980s as a way to iron out such phenomena.

The fact that these delicate features are real will force theorists to finesse their inflationary solutions and possibly even lead them to some novel physics on the way.

"Inflation doesn't predict that it should leave behind any kind of history or remnant, and yet that's what we see," Planck project scientist Dr Jan Tauber told BBC News.

CMB - The 'oldest light' in the Universe

Detail of CMB data
  • Theory says 380,000 years after the Big Bang, matter and light "decoupled"
  • Matter went on to form stars and galaxies; the light spread out and cooled
  • The light - the CMB - now washes over the Earth at microwave frequencies
  • Tiny deviations from this average glow appear as mottling in the map (above)
  • These fluctuations reflect density differences in the early distribution of matter
  • Their pattern betrays the age, shape and contents of the Universe, and more and follow me on Twitter: @BBCAmos


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  • rate this

    Comment number 231.

    " However, it is saying that God, not chance, is responsible for the universe. I'm a physicist and have no problem with believing that."

    I believe in one less god than you do.

  • rate this

    Comment number 230.

    No time to read this...I'm a busy bible man. Got adulterers to stone and children to sacrifice followed by a nailing of my own son to some wood.

  • rate this

    Comment number 229.

    This is all way beyond me

  • rate this

    Comment number 228.

    @213. Giles Jones
    Don't you know, God put fossils in the ground to test your faith?
    Most geologists in the 19th century were ordained ministers, to took it up to prove the validity of Genesis's account.
    Most changed their view based on the evidence they found,some preferred the proposition above.

  • rate this

    Comment number 227.

    @192 I think you'll find the authors of the gospels lived in an age where it was predominantly believed the world was flat and or the Sun revolved around the earth. To suggest the Bible even touches (1 or the sequel) the Science we know today is preposterous. If we don't know, we don't have to make up a devine creator. It's ok not to know and go and find out.

  • rate this

    Comment number 226.

    Genesis is clearly not intended to give a literal creation account, as the original author would have been fully aware that it juxtaposes two opposing accounts regarding the chronological order in which man and plants were created (see 1:11, 1:26, 2:5 and 2:7). However, it is saying that God, not chance, is responsible for the universe. I'm a physicist and have no problem with believing that.

  • rate this

    Comment number 225.

    The satellite shows Extra-Terrestrial parents also can't get their teenagers to switch off the lights.

  • rate this

    Comment number 224.

    This is all eye-wateringly difficult to imagine; I have always had a problem with imagining infinity. And for those who want to know what was there before the Big Bang - don't even go there. I take my hat off to all those physicists and mathematicians out there who try to make sense of it all

  • rate this

    Comment number 223.

    Captain Lort are you not concerned that God is playing tricks on the Human race? Because I don't see any other explanation for all this "evidence" unless god put it all there to fool those of us whose faith is not sufficiently strong.

    Personally I would not want to worship a supreme being that holds me and my entire race in such overt contempt, but I guess you are entitled to your own mistakes

  • rate this

    Comment number 222.

    I'm all for discovery /science but also weary at the same . are we knowing to much about everything? with every action there is an opposite reaction. People who believe in religions are constantly being proved wrong about the history of the universe and what then ? people lose faith that the most dangerous thing ? alot wil be thinking what's the point in life ???

  • rate this

    Comment number 221.

    You're all doomed! There is only one true faith:

  • rate this

    Comment number 220.

    If there is a god, if there is a heaven, if there is a devil who's tempting us with science... I'd take the devil any day of the week... "In the bible" god killed 2,476,633 people, the devil killed 10...
    This would also mean that the devil has saved millions of lives by giving us medical knowledge etc, while god abandoned us for thinking for ourselves...
    Fairy stories for scared children...

  • rate this

    Comment number 219.

    But God still created everything in six days, right?

  • rate this

    Comment number 218.

    201. znz

    " Science never "proves" anything; rather it continually finds, or fails to find, support for its current paradigm."

    You must be joking.

    The fact you lived past the age of 5, live in comfort and are able to express your views online via a laptop or mobile phone suggests otherwise.

  • rate this

    Comment number 217.


    No, the key point is that Steinhardt and Turek's model is cyclical, removing one of the fundamental objections to the Big Bang theory. This new data does not appear to disprove their alternative theory.

    What has been instructive is that some people have rated my comment 139 negatively simply for mentioning that there are dissenters to the current The Big Bang model.

  • rate this

    Comment number 216.

    Does Heaven show up as a different colour?

  • rate this

    Comment number 215.

    There will come a time in the future, where we will look upon those that were convinced of the "Big Bang" theory, in much the way we now look upon those that once thought that the earth was flat ....

  • rate this

    Comment number 214.

    @201 znz

    Poetry won't ever find a cure for any disease either, however pure and everlasting its truth.

    We NEED science (to invent the internet so we can all have a good argument!) ;p

  • rate this

    Comment number 213.

    >As PROVED by the bible, the earth is 6,000 years old

    Which is obviously rubbish. How do you explain dinosaurs and fossils then? You would expect some old cave paintings to have pictures of such beasts and you would expect human remains to be found near fossils, none of which happened.

    Please leave the history and archaeology to the experts.

  • rate this

    Comment number 212.

    @148: The Bible doesn't prove the universe is 6000 years old; dodgy human interpretations of biblical geneaologies "prove" the universe is 6000 years old.

    Meanwhile, the first verses of Genesis are fairly good descriptors of the Big Bang. Good: I dislike the idea of God working on human time-scales of 6000 years, but rather prefer the idea of him sculpting the universe over billions of years.


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