In 2009, the European Space Agency (ESA) launched its Planck space observatory mission to map the universe's oldest light at microwave and infra-red frequencies for the next four years. The data accumulated was analyzed and its initial findings first published in March of 2013.
An almost perfect Universe
The result was what ESA referred to as "the most detailed map ever created of the cosmic microwave background – the relic radiation from the Big Bang." ESA also said the image revealed an "almost perfect Universe" but that some anomalies were observed that would require further investigation.
"After this close examination, the standard model of cosmology is still standing tall, but at the same time evidence of anomalous features in the CMB is more serious than previously thought, suggesting that something fundamental may be missing from the standard framework," had said in a statement Jan Tauber, Planck Project Scientist at ESA.
Now, Planck's final data conclusions published on 17 July 2018 have finally reaffirmed the mission's preliminary findings to be correct. “So far the standard model of cosmology has survived all the tests, and Planck has made the measurements that show it," said in the agency's latest statement Tauber.
Standard model of cosmology confirmed
Compiled in a set of a dozen scientific papers by around three hundred researchers, the new research supports a model of the Universe defined by ordinary matter, cold dark matter and dark energy. Ordinary matter consists of the quarks and leptons that make up all we see and touch and is by far the lesser of all the matters (approximately 5%).
The other 95% of the Universe is reserved to cold dark matter and dark energy, the elusive force that may be responsible for the universe's accelerating expansion. The nature of these elements is still unknown especially since they cannot be detected directly and much of what is known about them today is still hypothetical.
The data also revealed that some anomalies that perplexed researchers. The most significant of these concerns the rate of expansion of the Universe known as the Hubble Constant.
It turns out that the rate calculated by the Planck mission differs by a few percents than the one estimated by the Hubble Space Telescope. Such a difference may seem insignificant to regular folk but Planck's team insists it creates a reason for concern.
"There is no single, satisfactory astrophysical solution that can explain the discrepancy," said deputy principal investigator Marco Bersanelli, of the University of Milan in Italy. Speculations regarding the cause for the discrepancy have been made ranging from the possibility of new physics to simply small errors.
Regardless, Planck's findings regarding an almost perfect Universe have made ESA's mission an undisputed success. “This is the most important legacy of Planck,” concluded Tauber.