Speaking exclusively to BBC News at the British Association Festival of Science, Dr Bernard Foing said the ark should be a repository for the DNA of every single species of plant and animal.
Dr Foing is head of Europe's Moon missions, so his thoughts on matters lunar should be taken seriously.
He is concerned that if the Earth were destroyed, there would be little or nothing left of the rich diversity of life on the planet. His solution is to build a DNA library on Earth's satellite.
"If there were a catastrophic collision on Earth or a nuclear war, you could place some samples of Earth's biosphere, including humans, [on the Moon]," he said.
"You could repopulate the Earth afterwards, like a Noah's Ark," he said.
For the time being though, Dr Foing is awaiting the arrival of Europe's first probe to the Moon.
The Smart 1 mission is due to arrive ahead of schedule in November. The spacecraft is testing a range of innovative technologies that should find their way on to many future European Space Agency probes.
It is the first of what he hopes will be a fleet of robotic spacecraft sent to the Moon. They would be used to build a lunar colony.
