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WMAP's measurements played the key role in establishing the current Standard Model of Cosmology

WMAP data are very well fit by a universe that is dominated by dark energy in the form of a cosmological constant

The anisotropies then are used to measure the universe's geometry, content, and evolution; and to test the Big Bang model, and the cosmic inflation theory

he map contains 3,145,728 pixels, and uses the HEALPix scheme to pixelize the sphere

The telescope's primary reflecting mirrors are a pair

that focus the signal onto a pair of

secondary reflecting mirrors.

shaped for optimal performance: a carbon fibre shell upon a Korex core, thinly-coated with aluminium and silicon oxide.

The secondary reflectors transmit the signals to the corrugated feedhorns that sit on a focal plane array box beneath the primary reflectors

The receivers are polarization-sensitive differential radiometers measuring the difference between two telescope beams.

To avoid collecting Milky Way galaxy foreground signals, the WMAP uses five discrete radio frequency bands

The WMAP's trajectory and orbit

The WMAP observes in five frequencies, permitting the measurement and subtraction of foreground contamination (from the Milky Way

Foreground contamination is removed in several ways

First, subtract extant emission maps from the WMAP's measurements; second, use the components' known, spectral values to identify them; third, simultaneously fit the position and spectra data of the foreground emission, using extra data sets

revealing the existence of features that challenge the foundations of our current understanding of the Universe

The image is based on the initial 15.5 months of data from Planck and is the mission's first all-sky picture of the oldest light in our Universe, imprinted on the sky when it was just 380 000 years old.

At that time, the young Universe was filled with a hot dense soup of interacting protons, electrons and photons at about 2700ºC

protons and electrons joined to form hydrogen atoms, the light was set free

As the Universe has expanded, this light today has been stretched out to microwave wavelengths, equivalent to a temperature of just 2.7 degrees above absolute zero.

that correspond to regions of slightly different densities at very early times, representing the seeds of all future structure: the stars and galaxies of today

According to the standard model of cosmology, the fluctuations arose immediately after the Big Bang and were stretched to cosmologically large scales during a brief period of accelerated expansion known as inflation.

Planck was designed to map these fluctuations across the whole sky with greater resolution and sensitivity than ever before

By analysing the nature and distribution of the seeds in Planck's CMB image, we can determine the composition and evolution of the Universe from its birth to the present day

because precision of Planck's map is so high, it also made it possible to reveal some peculiar unexplained features that may well require new physics to be understood

Since the release of Planck's first all-sky image in 2010, we have been carefully extracting and analysing all of the foreground emissions that lie between us and the Universe's first light

revealing the cosmic microwave background in the greatest detail yet

One of the most surprising findings is that the fluctuations in the CMB temperatures at large angular scales do not match those predicted by the standard model

their signals are not as strong as expected from the smaller scale structure

Another is an asymmetry in the average temperatures on opposite hemispheres of the sky

This runs counter to the prediction made by the standard model that the Universe should be broadly similar in any direction we look

a cold spot extends over a patch of sky that is much larger than expected.

The asymmetry and the cold spot had already been hinted at with Planck's predecessor

NASA's WMAP mission, but were largely ignored because of lingering doubts about their cosmic origin

One way to explain the anomalies is to propose that the Universe is in fact not the same in all directions on a larger scale than we can observe

In this scenario, the light rays from the CMB may have taken a more complicated route through the Universe than previously understood, resulting in some of the unusual patterns observed today.

ultimate goal would be to construct a new model that predicts the anomalies and links them together

we don't know whether this is possible and what type of new physics might be needed

the Planck data conform spectacularly well to the expectations of a rather simple model of the Universe, allowing scientists to extract the most refined values yet for its ingredients

dark energy, a mysterious force thought to be responsible for accelerating the expansion of the Universe, accounts for less than previously thought.

Normal matter that makes up stars and galaxies contributes just 4.9% of the mass/energy density of the Universe

Dark matter, which has thus far only been detected indirectly by its gravitational influence, makes up 26.8%, nearly a fifth more than the previous estimate.

Planck data also set a new value for the rate at which the Universe is expanding today, known as the Hubble constant

At 67.15 kilometres per second per megaparsec, this is significantly less than the current standard value in astronomy

The data imply that the age of the Universe is 13.82 billion years.

We see an almost perfect fit to the standard model of cosmology, but with intriguing features that force us to rethink some of our basic assumptions