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 411.

    Large research projects that seem to have 'no benifits' have infact given us some of the most usefull inventions, that have profound effects on all our lives.
    Take for example the MRI scanner, an invaluble tool for cancer diagnosis - developed at CERN whilst building the Large Hadron Colider (which I am sure is another big waste of money to you). People need to look at the bigger picture.

  • rate this

    Comment number 410.

    To all you god fearers out there - can one of you confirm which of the 2000+ gods that are worshipped today actually created the Universe - and then present some empirical evidence for it? Thanks.

  • rate this

    Comment number 409.

    What fantastic news, it's a shame the thread has been hijacked by the religious who are clearly worried that their god is fictional after all.

    Look we can't prove a god doesn't existing, how are we supposed to prove something that doesn't existing doesn't exist.

    What we can prove is that Genesis is incorrect, we now know how our planet came to be and no god was involved.

  • rate this

    Comment number 408.

    I'm sure someone has already pointed out an error in this article. The paragraph which refers to "slightly more matter" (37.1%) surely this is meant to say Dark Matter.

    Please don't start with the religious stuff, it's pointless. Science can't disprove God(s) & doesn't need to. The burden of proof lies firmly with the claimant.

    This is quite brilliant Science. The accuracy us staggering.

  • rate this

    Comment number 407.

    398.Simon Attwood
    Love it. hahaha

  • rate this

    Comment number 406.

    @351 Rihaines: Time and causality are properties of the universe itself. As such it may simply be meaningless to talk about "before" the universe because the concept of time doesn't exist outside it. Similarly talking about the "cause" of the big bang may be meaningless for the same reason.

    Our little human brains evolved in a cause and effect world, but reality may be more complex than that.

  • Comment number 405.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • rate this

    Comment number 404.


    Science can't disprove the existence of god


    Yes, well we can't disprove the existence of gods because that is how modern religion has set them up.

    He's in intangible, invisible all knowing power that hides all evidence of his existence. "Trust us though, he totally exists"

    Used to be the Greeks could just climb to the top of Mount Olympus and check. People got wise to that old scam.

  • rate this

    Comment number 403.

    @65. Good comment although "dialysis pumps, cordless tools, MRI, CAT scan machines" had little to do with space science.

  • rate this

    Comment number 402.

    @329 Did your God stop the meteor hitting Russia? Or was he happy to let it do so and wreak havoc on many poor innocent peoples' lives? Maybe he's not the good guy you presume he is. And I believe it's down to you to prove God is real, not vice versa.

    This is a great discovery. While not conclusive, it adds more weight to the Big Bang Theory.

  • rate this

    Comment number 401.

    "Could that idea that 'science' has all the answers be flawed?"

    That idea is indeed flawed, hence the requirement for us to continue conducting science

  • rate this

    Comment number 400.

    Check out the lowest rated comments on this article. I can't figure out if they're serious or just trolling! 67. Danny and 148. juventus18 are particular highlights.

    I always find it amazing when new data supports the current theories of the origins of the cosmos. I guess that's because i don't fully understand how those theories came about in the first place but it's fun to be fascinated :)

  • rate this

    Comment number 399.

    At this point in a “Science vs God” debate I always like to point out that what we now call the Big Bang theory was originally proposed in 1927 by Georges Lemaitre, a Belgian Catholic priest.

    The ACTUAL debate here is between the Big Bang and alternatives. Anyone who has taken the trouble to read the article will see that the latest data is not all good news for the Big Bang as Amos suggests.

  • rate this

    Comment number 398.

    ANYTHING becomes a religion the moment there is an intolerance to deviation from a strict guideline ....

    I'm detecting a lot of intolerance from "Team Atheist" towards people of a religious leaning.

    Religion is not the "root of evil" as is popularised by "Team Atheist". Rather it is our phylogenetic tendecy to form "US & THEM" tribes and always see "THEM" as the group to attack.

  • rate this

    Comment number 397.

    "this was written more than 1400 years ago in the QURAN"

    Please point out the pages which tell you:
    How to make a fire (without spontaneous combustion of vegetation)
    Make a Wheel
    Build a House
    Balance finances
    Make Electricity
    Produce Clothing
    Achieve optimum health
    How to perform CPR
    How to swim
    Distribute Food (other than loaves and fishes)
    I'll stick to reality thanks very much

  • Comment number 396.

    This comment was removed because the moderators found it broke the house rules. Explain.

  • rate this

    Comment number 395.

    I always thought the assertion that the BBC had more than its fair share of happy clappies was exaggerated, but having just had two posts removed for complaining about this potentially interesting thread being hijacked by religious fundamentalists has made me think again.

  • rate this

    Comment number 394.

    Ok so the big bang happened, I have some questions...
    What went bang?
    If this bang created the universe, where did the bang occur?
    Was there anything before the bang?

  • rate this

    Comment number 393.

    @352 Akoob. So it was written 1400 years ago, does that make it true? The Bible is Christian proof for Jesus/God, the Qu'ran is Muslim proof for Allah/God, the Mr Messy book is my son's proof for Mr Messy. I'm not saying you're right or wrong, but I am saying that age is not a reliable indicator.

  • rate this

    Comment number 392.

    @374 well said, it does get rather tiresome having the read the comments of either side.
    It's just cool that we have the ability to do these things and we should just appreciate it for what it is and leave the dogmatic predjudices and childish caricatures out of it.


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