Scientists have captured pictures of what they believe the universe looked like shortly after the “big bang”.
Acquired by ESA’s Planck space telescope, the most detailed map ever created of the cosmic microwave background is thought to be the relic radiation from the big bang, challenging the foundations of the 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 the 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 2 700ºC. When the 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.
This “cosmic microwave background (CMB)” shows tiny temperature fluctuations 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.
Because the 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.
“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. Such discoveries were made possible by the unique technologies developed for that purpose by European industry,” says Jean-Jacques Dordain, ESA’s director-general.
Picture: Cosmic microwave background seen by Planck