Royal Observatory extension will teach the wonder of the night sky

The Royal Observatory in Greenwich is gearing up for a massive £15m extension next year, to capitalise on growing interest in outer space.

A Victorian building which has been used for administration for decades is to be renovated, with new galleries and a 120-seat planetarium to treble the space for visitors to gaze at the stars. The Observatory hopes to complete the extension by 2007.

The Heritage Lottery Fund (HLF) has committed £7m towards the total cost of the new centre, to be called Time and Space.

The Observatory, which is part of the National Maritime Museum and a World Heritage Site in its own right, has backing for the project from the Particle Physics and Astronomy Research Council, which is keen to encourage greater public understanding of astrophysics.

The new galleries will create space for exhibitions on British achievements in astronomy and the underlying physical principles, such as gravity, and for interpreting recent developments in modern astronomy.

There is only one exhibition gallery in the existing Royal Observatory complex and the planetarium seats just 40. It always has a waiting list.

Roy Clare, the National Maritime Museum's director, said: "The Beagle-2 mission [to Mars] is the kind of episode that the Royal Observatory ought to be able to interpret for the public."

The main part of the museum is currently staging a show, The Beagle Voyages - from Earth to Mars, linking the original Charles Darwin Beagle mission of discovery to the Galapagos Islands with the Beagle-2 mission to Mars, because there is no room for it at the Observatory.

"It has proved a very popular feature, but the reality is that the Royal Observatory is the heart of this branch of science and the aspiration is that from 2007 onwards the public will be able to come and see both British and international astronomy science there," Mr Clare said.

The extended centre will include education facilities and a horology centre for the upkeep of the navy's chronometers, where the public will be able to view conservation in progress.

Mr Clare said the Royal Observatory was a "national treasure of international significance", and no maritime museum in the world had comparable collections going back to the beginning of the study of time and space.

Furthermore, the contribution of Britain today through, for instance, the European Space Agency, was often overlooked because of the attention paid to manned flights such as the space shuttles, he said.

Greenwich has been vital to the study of astronomy since 1675, when the first Astronomer Royal, John Flamsteed, conducted his early experiments in what is now the Royal Observatory.

This year, the centre has received around 700,000 visitors, a record for the site.

But more money has to be raised before building work can commence. Around £3.8m has been pledged by sources including the Department for Culture, Media and Sport, but plans are being finalised for a fund-raising campaign to secure the final few million required.

Sue Bowers, from the HLF, said: "New galleries, interactive experiments and educational opportunities will demonstrate how astronomy and time-keeping affect everyday life and inspire the imagination to question our place in the universe. Looking up at stars will never be the same again."