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 451.

    ... so why is the Universe ovoid rather than spherical.

  • Comment number 450.

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

  • rate this

    Comment number 449.

  • rate this

    Comment number 448.

    "I was once told of an Athiest man who walked into a room to see a mechanical model of the planets orbiting the sun, He was amazed and said who made this? A preist replied - oh noone - it just appeared here one morning.

    I don't beleive this is just nature - someone must have started all this off ...."

    That's all well and good but how you get from creator to organised religion is beyond me,

  • rate this

    Comment number 447.

    @433: So, not just religious, but sexist too. Must be a woman. See, works both ways.

    Also, as many, many people have said, science doesn't disprove God, any God, but the religious nuts like yourself can't handle the fact that there might not be one, and so have to jump in and defend your beliefs when something scientific comes along.

  • rate this

    Comment number 446.

    Can Science ever Prove/Disprove the existence of God?

    Science, by it's very nature, does not deal in absolutes. Every scientific theory ever made has the potential, however small, to be disproven. When dealing with such an uncertainty as an omnipotent being, there is always the chance, however slim, that God is "deceiving" us. Therefore his existence can never be fully proven or disproved.

  • rate this

    Comment number 445.

    @ 435 Dreamweaver
    @330 - Dude, you are one seriously twisted individual!
    @329 Someonewhocares - what is it you care about exactly? Not freedom of speech or clarity of thought I take it?
    @327 Jabdi - 'religious' texts are constantly being freshly provided by new thinkers. They're not all fingered grubby brown scrolls laden with mindless superstition & void of sound guidance, but I get your point.

  • rate this

    Comment number 444.

    One interesting thing in the comments is how many people seem to have an odd sense of what "proof" means. They demand unreasonable levels of proof for everything.

    The truth is that with the exception of say maths theorems it is not possible to prove anything. All we can do is present the evidence for something and seek agreement from as wide range of experts and other evidence as we can.

  • rate this

    Comment number 443.

    To all the non believers here ....

    I was once told of an Athiest man who walked into a room to see a mechanical model of the planets orbiting the sun, He was amazed and said who made this? A preist replied - oh noone - it just appeared here one morning.

    I don't beleive this is just nature - someone must have started all this off ....

  • rate this

    Comment number 442.

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



    No it wasn't !
    Modern English did not exist (by definition) in circa 600 AD ;-)

  • Comment number 441.

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

  • rate this

    Comment number 440.

    @418 What the all things that science has given us are you talking about? disgarded liquid? (sperm=human) to develop? what..

    Sorry Mr Amos ive suffered all i can, and i really enjoy reading your columns.. Look forward to next time.

  • rate this

    Comment number 439.

    "I have some questions..."
    In the `standard' theory (but bear in mind we *know* this theory is provisional, pending the development of a quantum gravity theory):
    "What went bang?" - everything, including space (and time).
    "where did the bang occur?" - everywhere, since everywhere was in one place.
    "Was there anything before the bang?" - no, not even time (or space).

  • rate this

    Comment number 438.

    Nice picture of coloured dots science, can we join them up yet or we wait 6000 years? Am off now so have deep meaningfulls about the illusion that you have been sold, floods,dead animals all round the world, wars and rumors of wars, famine, yada yada yada. Proof is coming, shame i won't be here to see-science will save you....not.

  • rate this

    Comment number 437.

    @417.Paul H
    'After all planets orbit stars and the same principal seems to apply to atoms ... Is this some sort of common denominator?'
    You are reffering to the Bohr model of an atom which is a very simplistic model, in reality what happens in atoms is much more complex and doesn't really look anything like a solar system.

  • rate this

    Comment number 436.

    @384 Dave

    "So can we finally stop wasting money on religious nonsense now and start spending money of the debt crisis."

    Money. Now there's a religion based on a made up entity that EVERYONE believes in.

  • rate this

    Comment number 435.

    #397, are you serious? I'm looking on my bookshelf at a book titled "How to do everything with HTML". It doesn't tell me how to make fire, perform CPR, distribute food or do any of the other things you seem to regard as essential to represent reality but it does a good job of explaining how to write HTML.

  • rate this

    Comment number 434.


    The happyclappers will tell you only god existed before the BB and that it was him/her that lit the touchpaper.
    The scientists will tell you they simply just don't know and it's all a theory, but they know for a fact that it wasn't god despite being unable to disprove it.

  • rate this

    Comment number 433.

    I think you're totally wrong. This comments thread has been hi-jacked by the anti-goddists, whose inability to contemplate an Intelligent Designer has put them at the defensive because of the staggering beauty of the universe which in itself is evidence of God. The least-reasoned comments here are from those guys ... and yes, they're almost certainly guys!

  • rate this

    Comment number 432.

    We don't need science to disprove religion, common sense disproves religion.

    Was there anything before the big bang? The theory is that the big bang created time so technically there was nothing before the big bang but who knows.

    There was no god though, that asks more questions than it provides answers.


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