The first European spacecraft to visit the Moon was launched on 28 September. The craft is using an ion-powered thruster — an experimental propulsion system that the European Space Agency (ESA) hopes will carry probes to other planets.

The craft, called Small Missions for Advanced Research in Technology 1 (SMART-1), blasted off aboard an Ariane 5 rocket from French Guiana. It will now slowly spiral towards the Moon, without the use of typical chemical propellants.

When it arrives, SMART-1 will map the distributions of various elements on the lunar surface, says mission scientist Sarah Dunkin of the UK's Rutherford Appleton Laboratory: “It will help us distinguish between theories of the Moon's creation.”

The ion thruster can only push the 367-kg craft with a force equivalent to a sheet of paper resting on an open hand. The journey will take a year and a quarter, rather than the few days taken by the Apollo missions. But given its bargain price of €100 million (US$120 million), ESA is willing to wait.