Final answer:
The Earth is estimated to be approximately 4.6 billion years old, based on radiometric dating of minerals, lunar samples, and meteorites. This aligns with the age of the solar system.
Step-by-step explanation:
The Earth is estimated to be about 4.6 billion years old. This age is determined through various forms of radiometric dating using rocks and minerals found on Earth, as well as meteorites from space. The oldest rock minerals found on Earth are about 4.404 billion years old, discovered in Australia. Additionally, the age aligns with the estimated age of the solar system, further solidified by dating lunar samples and primitive meteorites. These findings suggest that the Earth and other planetary bodies formed relatively quickly after the solar system's formation.
Geologists utilize abbreviations like Ma (millions of years) and Ga (billions of years) to reference time periods in Earth's geologic history. For instance, the extinction of the dinosaurs is noted as occurring 66 Ma (million years ago). Accurate knowledge of Earth's age assists scientists in understanding the timeline of events in the planet's extensive history.