Joining ESO will give Britain access to Chile's Very Large Telescope. Credit: ESO

Britain will join the European Southern Observatory (ESO) in 2002. Last week's science spending plan includes funds for the Particle Physics and Astronomy Research Council (PPARC) to pay for ESO membership.

The move will give British astronomers access to the new Very Large Telescope, which has four 8.2-metre mirrors, at Mount Paranal in Chile. This will require a 'joining fee' of £70 million (US$98.5 million), plus £12 million per year.

But the timing of the payments must be decided before British astronomers learn what other projects must be sacrificed so that they can use the ESO's facilities.

The PPARC's budget, which will rise to £232 million by 2003–04, includes £10 million over each of the next three years for membership of the ESO. If the joining fee were to be paid in one go, the consequences for the rest of the PPARC's programme would be disastrous. But in practice a deal will be thrashed out to spread the payments over several years. “There is flexibility on the timescale,” says ESO director-general Catherine Cesarsky.

But some cuts to the PPARC's existing research portfolio are inevitable. “What I hope is that the PPARC will consider its whole programme,” says Martin Rees of the University of Cambridge, Britain's Astronomer Royal.

Ground-based astronomy is expected to bear the brunt of any cuts, however, and an expert panel of astronomers has been called in to prioritize the current range of projects.