Q & A

These blue, spherical rocks have fascinated scientists. Where were they found?

  1. At the bottom of the Pacific Ocean.

    Wrong. The Pacific Ocean is the deepest ocean on Earth. Its deepest point is the Mariana Trench, which stretches seven miles below the Earth’s surface.

  2. On the surface of Mars.

    Correct! Scientists call these rocks “blueberries” for their spherical shape. They were discovered by the Opportunity Rover, which has now retired after 15 years on the red planet.

  3. In the Jack Hills in Australia.

    Not quite, although the Jack Hills are home to some very interesting rocks. The oldest rock on Earth was found there. It was a zircon that dates back 4.4 billion years. The Earth is 4.54 billion years old.