Composition, Age of Universe Refined by Planck Observations

Data from the European Space Agency’s (ESA’s) Planck space telescope reveals that the universe is slightly older than previously thought, and the ratio of normal matter to dark matter and dark energy is somewhat different.

Observations of the Cosmic Microwave Background (CMB) by two U.S. spacecraft, the Cosmic Background Explorer (COBE) and the Wilkinson Microwave Anisotropy Probe (WMAP), profoundly changed scientists’ understanding of the composition of the universe, especially dark energy and dark matter.  NASA astrophysicist John Mather and George Smoot of Lawrence Berkeley National Lab won the 2006 Nobel Prize in Physics for COBE’s ground breaking cosmological findings, which were continued by WMAP.  The Hubble Space Telescope resolved long held disputes about the age of the universe.   ESA’s Planck space telescope, to which NASA provided “mission enabling technology for both of [its] science instruments,” is refining all those measurements.

Data from Hubble determined that the universe is 13.7 billion years old.   The new data from Planck increases the age to 13.82 billion years.

Dark energy and dark matter together comprise more than 90 percent of the universe.   Neither can be seen and scientists are still trying to determine exactly what they are.   The existence of dark matter is inferred by gravitational effects and was first postulated in the 1930s.   Dark energy is theorized to be a force that is accelerating the rate of expansion of the universe.

After the most recent analysis of WMAP data, the mass-energy content of the universe was calculated as 4.5 percent normal matter, 22.7 percent dark matter, and 72.8 percent dark energy.   Planck’s data refines that to 4.9 percent normal matter, 26.8 percent dark matter and 68.3 percent dark energy.

Image credit: European Space Agency

Data from Planck were used to create this image of the universe when it was just 380,000 years old and “shows tiny temperature fluctuations that correspond to regions of slightly different densities, representing the seeds of all future strcutures:  the stars and galaxies of today,” according to ESA.

Image credit: European Space Agency