BBC Science Correspondent Sue Nelson reports

The warning is being made at an international conference in Vienna which will highlight the increasing range of problems facing astronomers. Although telecommunications operators work within certain specified bandwidths, their signals are so powerful, they often "leak" into the frequencies used by astronomers.

The astronomers' signals are very faint

Radio telescopes like the one used at Jodrell Bank, near Manchester, can detect the faintest signals from the deepest regions of the Universe to learn more about the origins of the cosmos and to identify molecules in space that are essential for life.

"One of the greatest discoveries which was made by radio astronomers was to find the dying echo of the Big Bang," says Cambridge astronomer Dr Simon Mitton. "As a direct result of such work, we now believe that our Universe came into existence out of nothing in a huge explosion." Such groundbreaking research, he says, is becoming increasingly difficult.

Astronomers are asking the United Nations for tighter regulations on mobile phones satellite transmitters to secure a future for ground-based astronomy.

Mobile on the Moon

Dr Simon Mitton: The problem could hamper the search for extraterrestrial life

"If you took your standard mobile phone and put it on the moon, it would be among the top three radio astronomy sources," says Professor Derek MacNally from the University of London.

The communications industry says it is aware of the problem and will work to minimise the leakage.

"Yes, we should not try to interfere with them and that is our plan - that is what we try to achieve," says Richard Aspden of ICO Global Communications.

Derek MacNally: Mobile phones are a source of interference

"But we've all got to use the radio frequency spectrum and it is important to provide the safety and security of mobile communication services worldwide."

Light pollution from street lamps is already a common problem for astronomer using optical telescopes. The most important observations now have to be made using equipment sited at altitude and well away from urban areas in locations such as Chile and Hawaii.

Astronomers also face the prospect of space mirrors in the near future. These are giant discs of reflective material that would shine light down onto areas of the Earth's surface that were experiencing very short days because of their latitude.