Okay so 100 million years seems like a big mistake on the part of Astronomers, but in the astronomical community its a small adjustment.
Highest detail map of the CMBR ever produced Credit: ESA/Planck
Today the most detailed map of the CMBR ever captured was released by the Planck telescope group at the ESA. Based on 15.5 months of data, it shows the tiny temperature variations that were present when the universe had a temperature of 2700 degrees Celsius and an age of just 380,000 years (trust me that’s small on astronomical scales). This is the point when the dense soup of protons and electrons formed hydrogen atoms, and the universe became transparent.
As the universe has expanded the light has stretched out to microwave wavelengths and now has a temperature of 2.7 degrees above absolute zero, -270 Celsius The tiny temperature fluctuations on the order of millionths of degrees visibly correspond to the structure that would eventually map out the structure of galaxies and galaxy clusters throughout the universe.
The estimate of the age of the universe is now more precise as well, since the CMBR measurements give precise constraints to the Hubble constant, used in the Lambda-CDM model ...