By Dr David Whitehouse BBC News Online science editor

The world famous radio telescope at Jodrell Bank in northwest England is back in action, with an improved surface that allows it to make new observations.

After two years of work, the University of Manchester's Lovell Telescope has a brand new surface. Made of galvanised steel at a cost of �2.5m, it has given the 45-year-old telescope a new lease of life.

Professor Andrew Lyne, director of Jodrell Bank, says he is delighted to have the flagship instrument back in use and he looks forward to the rejuvenated telescope keeping the observatory at the forefront of astronomical research for many years to come.

Next summer will bring the final phase of the upgrade in which each of the 340 panels that make up the 76-metre-diameter surface will be adjusted to make the whole surface accurate to within a millimetre.

More sensitive

Sir Bernard Lovell, first Director of the Observatory, who watched as the new surface was revealed, says he never expected the telescope to have an operational life of more than 15 years and was immensely pleased to see it still in use.

During resurfacing

With the new surface and advanced electronics, the telescope is now more than 30 times more sensitive than when it was built in 1957.

With a more accurate surface it will be able to scan the skies at a wider range of frequencies in its ongoing studies of pulsars, the formation of stars in our own galaxy and faint radio galaxies and quasars in the far reaches of the Universe.

In addition to its use as a single telescope, the Lovell Telescope is a key element of the UK's Merlin high-resolution network of radio telescopes.

The upgrade will more than double the sensitivity of Merlin and allow new areas of astrophysical study, producing images whose detail exceeds that of the Hubble Space Telescope.

Jodrell Bank astronomers point out that the Lovell telescope is regularly linked to telescopes in Europe and around the globe to make observations with the highest resolution in all astronomy.