In the film Contact, extraterrestrial life announced its presence to Jodie Foster using radio signals and the universal language of mathematics. It would be nice to think that the public, who flocked to see the film, is now sensitized to the cultural importance of radioastronomy, and might be dismayed to learn of its threatened obliteration by mobile telephones.

Pollution of radiofrequencies is perpetrated by commercial satellite companies and permitted by national governments. Their meeting point is the International Telecommunication Union (ITU), a United Nations body which allocates the radiospectrum and controls radio regulations. The ITU accommodates commercial needs by ignoring one of its own rules: “harmful interference should not be caused to radioastronomy”. An unwritten qualification — “provided that it does not cost too much” — dominates decisions. Thus the ITU has agreed toothless and non-mandatory guidelines for regulating the quality of satellite transmissions (see page 103). These are insufficient to stop overspill emissions.

In the same way that they enforce regulations to protect rare habitats and designated areas of scientific interest, national governments should respect their obligations to radioastronomy. They should instruct their ITU delegates — and the ITU is only as good as its delegates — to make no concessions to industrial lobbies that risk pollution of radio bandwidths of scientific importance. Yet they do not.

Individual governments also have power outside the ITU because they are responsible for issuing national licences. They should reject pending licence applications from Iridium, which wants to operate a multisatellite mobile telephone system with no guaranteed protection for radioastronomy frequencies. The customers of Iridium, and similar companies, must be forced in this way to pay for nonpolluting systems.