For adults

Astronomy: An Introduction  (Faber, 1978)

Star Atlas  (Jonathan Cape, 1979, with Simon Mitton)

Key Definitions in Astronomy  (Frederick Muller, 1980)

Invitation to Astronomy  (Basil Blackwell, 1986, with Simon Mitton)

Concise Dictionary of Astronomy  (Oxford University Press, 1991)

The Penguin Dictionary of Astronomy  (1992, revised edition 1998)

The Great Comet Crash  (Cambridge University Press, 1995, contributor, and co-editor with John Spencer of Lowell Observatory)

Gems of Hubble  (Cambridge University Press, 1996, with Stephen Maran)

Pluto and Charon : Ice worlds at the ragged edge of the solar system (Wiley, Inc, New York, 1997, with with Alan Stern)

The Cambridge Dictionary of Astronomy (Cambridge University Press, 2001)

Lifting Titan's Veil (Cambridge University Press, 2002,  with Ralph Lorenz)

Asteroid Rendezvous: NEAR Shoemaker's Adventures at Eros (Cambridge University Press, 2002; co-editor with Jim Bell)

Pluto and Charon : Ice worlds at the ragged edge of the solar system ( 2nd edition) (Wiley, Germany, 2005, with Alan Stern)

The Cambridge Illustrated Dictionary of Astronomy (Cambridge University Press, 31 December 2007)

Titan Unveiled (Princeton University Press, 2008; co-author with Ralph Lorenz)

For children and younger readers

Discovering Astronomy  (Longman, 1979; co-author Simon Mitton)

Children’s Britannica  (astronomy articles) (1984)

Discovering the Planets  (Eagle Books, 1991)

Oxford Children's Encyclopedia (all astronomy and some other articles) (1991)

Oxford Astronomy (1st published as The Young Oxford Book of Astronomy)  (Oxford University Press, 1994; co-author Simon Mitton)

Galileo  (in 'What's their story?' series, Oxford University Press, 1997)

Zoo in the Sky  (Frances Lincoln in the UK and National Geographic in the USA; 1998; for young children)

Aliens  (Walker Books UK, Candlewick Press USA, 1998; for children)

Marshall Children's Guide to Astronomy/Scholastic Encyclopedia of Space (Marshall Edition in UK and Scholastic in USA, 1998; co-author Simon Mitton; for children). Shortlisted for Rhone-Poulenc Junior science book prize, 1999.

Kingdom of the Sun (Frances Lincoln in the UK and National Geographic in the USA, 2001). English Association (UK) Award for best Children's Illustrated Books 2001, 4-11 yrs Key Stage 2 category.

Young Oxford Encyclopedia of Science: Stars and Planets (Oxford University Press, 2002)

Once Upon a Starry Night (Frances Lincoln and National Geographic, 2003)

Zodiac (Frances Lincoln, 2004)

Let’s Go to the Planets!(Oxford University Press, 2006)

The Planet Gods(This is a revised edition of Kingdom of the Sun: Frances Lincoln in the UK and National Geographic in the USA, 2008)

In press

Eyewitness Moon(Book and CD, Dorling Kindersley, 16 February 2009)

Editorial consultany and revised editions for Dorling Kindersley Books (examples)

2002 The Way the Universe Works by Robin Kerrod and Giles Sparrow

2004 Revealed: Space by Alex Barnett

2004 e.encyclopedia Science

2004 and 2007 Night Sky Atlas by Robin Scagell

2005 Nature Activities: Stargazer by Ben Morgan

2006 Pick Me Up - Stuff You Need to Know by David Roberts and Jeremy Leslie

2006 - 2007 Eyewitness: Universe

2007 Eyewitness: Astronomy

2007 Eyewitness: Time and Space

2007 Space by Carole Stott

2008 Space Encyclopedia by Heather Couper and Nigel Henbest