Stephen Hawking looks into the future, and argues for the necessity, of space exploration.
Hawking claims that due to the threats face by Earth, from climate change to population growth, we need to start populating a new planet within the next 100 years. The most likely planet that could sustain human life is Proxima B, over four light years away.
This programme looks at the various technological challenges that scientists face in order to make this journey a possibility.
The Search for a New Earth is on BBC Two at 21.00