Could it hold the key to life? A space probe has returned from a seven-year journey into the solar system. Scientists hope it might be carrying our very earliest ancestors.
Yes, this really DID land from outer space

Glossary
Asteroid - A small body in space, made of metal and rock material. Asteroids usually orbit the sun, but if knocked off course they can be drawn into Earth’s gravity and fall towards it.
Universe - Everything. Including all of time and space and its contents.
Nasa - The National Aeronautics and Space Administration, responsible for the US space programme.
Pessimism - Always expecting the worst.