Most detailed 'blueprint' of ancient Universe released
MANILA, Philippines - Call it a "blueprint" of the cosmos: the most detailed map of "fossil" radiation from the Big Bang was released Thursday, March 21, shedding new light to our understanding of the origins of the Universe.
The European Space Agency (ESA) released the map of the early Universe, which shows the most detailed plot of cosmic microwave background radiation (CMB), a type of radiation that dates back to the forming years of the Universe immediately after the Big Bang.
Data on this new map - a seemingly random collection of blues, oranges, reds that represent the faint, ancient microwave radiation that is present throughout space - was based on data collected over 15 months by the Planck space telescope.
This, according to the ESA, gives scientists "excellent confirmation" of the standard model of cosmology, with "unprecedented accuracy."
It also unveiled several notable anomalies and refinements to some scientific ideas about the origins and composition of our Universe.
What is the CMB?
The CMB is what we can call a "shockwave" from the Big Bang.
Immediately after the Big Bang, scientists theorize, the very high temperatures prevented matter from forming, so all matter was mixed with each other, including light. As a result, the Universe was opaque, with light not traveling in straight lines and thus not propagating.
As the Universe cooled down from the cosmic event, atoms started forming, and matter became neutral; this allowed light to start traveling freely, and the Universe became transparent.
That first light, estimated to have 'formed' when the Universe was aged 370,000 to 380,000 years old, is the CMB, and it is "fossilized" in the universe.
Since then, the Universe expanded and cooled down, as did the CMB. Now, this background radiation is all around us, in microwave frequencies equivalent to just 2.7 degrees above absolute zero.
There are, however, temperature variations in the radiation that is measured - measured in micro Kelvin - which show the density differences of matter at the beginning of time, and thus, representing the "seeds" of all future structures in the Universe - the stars and galaxies of today, the ESA said.
The map has altered some of the basic ideas that scientists have been using as a basis for understanding the universe.
One, data suggests that our Universe is slightly older than we thought: 13.82 billion years old, or older by 50-100 million years compared to previous calculations.
This is because the data showed the Universe is estimated to be expanding a bit slower than thought: the Hubble's constant, the estimated expansion rate of the Universe, is now 67.15 +/- 1.2 kilometers/second/megaparsec (km/sec/Mpc).
(A megaparsec is around 3.26 million light-years.)
It also made scientists adjust their "recipe" of the composition of the Universe.
It suggested that the cosmos is made up of 4.9% "normal matter," or the things that make up stars, galaxies, and us, up from the earlier estimate of 4.5%.
In turn, the estimated composition of "dark matter," which has so far been detected only by its gravitational influence, is up from 22.7% in earlier calculations to 26.8%, based on the Planck data.
This leaves scientists with an estimate of 68.3% "dark energy," the still mysterious force which is believed to be the cause of the Universe's expansion. Earlier estimates put this figure at 72.8%.
"[The] Planck data conform spectacularly well to the expectations of a rather simple model of the Universe," the ESA said.
The data from the mission also revealed that there is an uneven distribution in the average temperatures of the radiation, which did not conform with the earlier assumption that the Universe is uniformly similar throughout.
Data also revealed temperature fluctuations are not exactly a match to what they originally predicted, and signals are weaker. There is also difference in the temperatures across the sky, with the southern sky slightly warmer.
It also showed a "cold spot," which confirms a finding by the earlier Wilkinson Microwave Anisotropy Probe (WMAP).
Prior to the Planck mission which was launched in 2009, there were two projects that also studied the CMB: the Cosmic Background Explorer or the COBE in 1989, and the WMAP in 2001, both under NASA.
The Planck mission "refined" the map of CMB across the sky, producing the most detailed version so far.
"The extraordinary quality of Planck’s portrait of the infant Universe allows us to peel back its layers to the very foundations, revealing that our blueprint of the cosmos is far from complete," said Jean-Jacques Dordain, the director general of the ESA.
"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," said Jan Tauber, one of the scientists involved in the Planck project.
The Planck mission is continuing its scanning of the sky, and will release its full results by 2014. - Rappler.com