New evidence has shown the most commonly given age of the solar system is wrong.
The equations used to derive the age of it from radiometric dating of numerous isotopes was fundamentally flawed because it assumed that the ratio of certain isotopes was the same. Detailed new measurements have shown it's not.
This "implies substantial uncertainties in the ages previously determined by Pb-Pb dating". So astronomers have had to recalculate the age of the solar system given this new information.
The old age: 4.6 billion years.
The new age: 4.6 billion years.
Oh wait.... let me zoom in a bit and add a few more significant digits.
Old: 4.567 billion years.
New: 4.566 billion years.
See! See! Scientists got it wrong!
But wait.... how it that "substantial"? It still doesn't mean that the Earth is 6,000 years old and Jesus rode around on a dinosaur.
In the full geological history of the Earth, that ~1 million years isn't that important. But on the timescales in which solar system formation takes place, it's a decent chunk of time and we need a good understanding of timescales to put into models to make them as accurate as possible.
This won't mean a rewrite of any high school textbooks since the significant digits are rounded off before this change is even noticed, but this is yet another example of how science is self correcting and is constantly challenging its own assumptions.
Brennecka, G., Weyer, S., Wadhwa, M., Janney, P., Zipfel, J., & Anbar, A. (2009). 238U/235U Variations in Meteorites: Extant 247Cm and Implications for Pb-Pb Dating Science DOI: 10.1126/science.1180871