Japan is to send a space mission to Mars today to retrieve a piece of its moon Phobos and bring it back to Earth.  

If it is successful, this will become the first time a sample has been returned from Mars or its moons to be analysed in laboratories on Earth.

The unmanned spacecraft will arrive near Mars one year later, where it will orbit its moon Phobos for up to three years before landing and collecting at least 10 grams of material from the surface.