Internet search company Google is offering a $30m (£15m) prize purse in a robotic race to the moon.

The competition is run by the X Prize Foundation, an educational non-profit prize organisation.

Private companies around the world will compete to land a robotic rover on the moon .

The first prize of $20m (£10m) will be offered until the end of 2012, and will then drop to $15m (£7.5m) until 2014.

The competition is designed to stimulate research to dramatically reducing the cost of space exploration, said the X Prize Foundation’s chairman and chief executive Dr. Peter H. Diamandis.

The top prize of $20m (£10m) will be given to the private firm that lands a robot on the moon which is able to roam the lunar surface for at least 500 metres and send video, images and data back to earth.

A prize of $5m (£2.5m) will be given for second place.

Google said it would give bonuses of $5m (£2.5m) if the rovers complete other objectives such as travelling further on the Moon, taking pictures of Apollo hardware, finding water-ice and surviving the freezing lunar night.