Multiple choice general knowledge science & technology How old is the Earth? 400 billion years old 4.6 billion years old 3500 million years old 10 million years old Reveal answer Fill a bubble to check yourself B Correct answer Explanation The Earth formed approximately 4.6 billion years ago, based on radiometric dating of meteorites and Earth's oldest rocks. This is well-established in geology and represents the age of our solar system's third planet.