The exploration of the Solar System is an expensive endeavour. The greater the number of nations that engage in peaceful planetary research the better.
In a rapidly changing and uncertain economic climate, tough choices will have to be made. Just a month or so ago, research on Titan took a blow when a proposal to NASA for a mission to this fascinating moon of Saturn was beaten by a proposal for exploring the icy Jovian satellite Europa. The European Space Agency (ESA) will probably undertake a parallel mission to Ganymede, another body in Jupiter's realm.
For now, it seems that the world's two premier exploration agencies do not have the money for additional missions, and the future of the Russian space program is unclear. However, the entry of nations such as China, Japan and India into space exploration has expanded the options. No more will the world have to rely solely on the space veterans to satisfy its curiosity about Earth's neighbours in the Solar System.
Even Iran took a first step towards the development of a functional space programme by successfully launching a tiny satellite. Iran itself naturally took particular pride in this achievement, but western media have been quick to highlight the potential military and political implications of the launch. Five decades after the launch of the Soviet satellite Sputnik, it seems that space, nationalism and geopolitics are just as intertwined with each other today as they were then.
The entry of more players and their desire to explore is an important and positive development: the new entrants have burgeoning economies and no shortage of scientific talent, and their space programmes are already injecting new life into the study of the Moon (see Feature on page 234). Because of its close proximity to Earth, the Moon is an ideal platform for newcomers in the space game to perfect the art (and science!) of building and launching spacecraft and probes. In the long-run, this may allow NASA and ESA to focus more on far-away planetary bodies.
Of course, more missions from a larger number of nations will require greater international cooperation. This is an opportunity as well as a challenge. The signs are good: India's Chandrayaan-1 spacecraft carries scientific instruments from the US and Europe.
As the recent collision between two satellites suggests, space is getting crowded. Nevertheless, the scientific benefits from a more diverse field of space-going nations are likely to outweigh the costs.