An unlikely star in the universe

Before 1930, space was thought to be just that - a completely empty void.

Then, in 1930, Lick Observatory astronomer Richard Trumpler proved that it was far from empty. It contained dust. And this dust not only dimmed the light travelling from distant stars, but also made it redder.

Dust is everywhere - it is being blown out of comets, it is formed by condensation in the outer atmospheres of cool giant stars and it is mixed up with gas in giant molecular clouds. It is also a vital ingredient in the production of new planets and stars.

Doug Whittet, a much-respected cosmic "dustman", has added 30 per cent more text in updating his Dust in the Galactic Environment (1992). Much is made of the exciting new results that have come from space missions such as the Hubble Space Telescope, the Cosmic Background Explorer and the Infrared Space Observatory. The effects of dust in protoplanetary discs, around nearby stars and in the discs and cores of distant galaxies, are emphasised.

Whittet explains how our observations of the infrared spectra of cool dust, and of the intensity, colouring and polarisation of starlight, have led to an understanding of the composition and distribution of dust.

He also delves into how it has helped us measure the magnetic fields in galactic arms and understand the chemical process in gas clouds that lead to the production of complex molecules and the building blocks for life.

The fact that dust is now at the forefront of modern astrophysical research owes much to this excellent textbook.

David W. Hughes is professor of astronomy, University of Sheffield.