- The Hadean (IPA: /heɪˈdiːən, ˈheɪdiən/ hay-DEE-ən, HAY-dee-ən) is the first and oldest of the four known geologic eons of Earth’s history. The Hadean eon started with the planet’s formation about 4.54 Bya, now defined as (4567.30 ± 0.16) Mya set by the age of the oldest solid material in the Solar System found in some meteorites about 4.567 billion years old. The proposed interplanetary collision that created the Moon occurred early in this eon, and the Late Heavy Bombardment is hypothesized to have occurred at the end of the eon. The Hadean ended 4.031 billion years ago, and was succeeded by the Archean eon.
- Dayton, Ohio (Wikipedia)
Dayton (/ˈdeɪtən/) is a city in and the county seat of Montgomery County, Ohio, United States. A small part of the city extends into Greene County. As of the 2020 census, the city proper had a population of 137,644, making it the sixth-most populous city in Ohio. Dayton anchors the state’s fourth-largest metropolitan area, the Dayton metropolitan area, which had 814,049 residents. Dayton is located within Ohio’s Miami Valley region, 50 miles (80 km) north of Cincinnati and 60 miles (97 km) west of Columbus. It is a principal city of the Dayton–Springfield–Sidney combined statistical area, home to a population of 1,086,512.