By Lucy and Stephen Hawking
George's best friend Annie needs help. Her scientist father, Eric, is working on a space project - and it's all going wrong. A robot has landed on Mars, but is behaving very oddly. And now Annie has discovered something wierd on her dad's super-computer.
Is it a message from an alien? Could there be life out there? How do you find a planet in outer space? And if you could talk to aliens, what would you say?