Rocks from Mars
Nobody has brought back a rock from Mars yet. But some Mars rocks have come to us by themselves.
Mars is the red planet. It is red because its dust contains iron that has rusted.
Long ago, big space rocks crashed into Mars. The crashes were so powerful that some rocks were thrown off Mars and out into space.
Those rocks drifted around the Sun for millions of years. A few of them met Earth and fell as meteorites.
How do scientists know they came from Mars? Some of them have tiny bubbles of gas trapped inside. That gas is a match for the air of Mars, which was measured by spacecraft that landed there.
Scientists have found a few hundred meteorites from Mars. They are some of the most precious rocks on Earth.
Right now, a rover called Perseverance is collecting rock samples on Mars and sealing them in tubes. Scientists hope a future mission will bring them home.
There are meteorites from the Moon too. Scientists have found several hundred of them, mostly in deserts and in Antarctica.