ALMA will gather highly red-shifted radiation from the furthest stars and galaxies, and will allow astronomers to observe cool dark objects such as brown dwarfs and interstellar dust clouds. The ALMA team hope to achieve a resolution as good as the Hubble Space Telescope but for sub-millimetre images.

The site at Chajnantor, in the Atacama desert is very dry as well as high up, making it ideal for sub-millimetre astronomy as radiation at these wavelengths is usually absorbed by water vapour in the atmosphere.

Japan has also expressed an interest in joining ALMA and merging its competing project making ALMA a global research facility – the first outside particle physics. “This is certainly new for ground based astronomy, ” says Richard Wade of the Rutherford Appleton laboratory, and UK project manager on ALMA.

Building work at the site will not be completed until 2009, but intermediate observations, made with just a few antennae, should start in 2005.