So how old is our planet, and how do we even know its age? Earth formed about 4.54 billion years ago, about 10 million years after the solar system was born. After a gigantic cloud of gas ...

that Earth was infinitely old. In contrast, ancient Indian scholars, who envisioned a universe that repeatedly expanded and collapsed, estimated the Earth's age to be around 1.97 billion years.

The planet Earth is about 4.5 billion years old. Earth spins at 1000 miles per hour. It takes 24 hours to complete a full rotation. It's daytime on the side of the Earth that faces the Sun and ...

The clock would tell him how long that ore -- and by extension, the earth's crust -- had existed. His observations and calculations put Earth's age at 2.2 billion years. This was a dramatic ...