Melvyn Bragg and guests discuss the cosmos, from the origins of the universe to dark matter and dark energy.

In Our Time is a linchpin of the Radio 4 schedule, attracting over 2 million listeners a week since its launch in 1998. Erudite, edifying and enlightening, it tackles serious ideas succinctly, providing fascinating insight into subjects ranging from the Fibonacci Sequence to Frida Kahlo.

In this special thematic anthology, we traverse the solar system, the galaxies and the multiverse, voyaging across space to explore 25 celestial objects and phenomena. Included are programmes on the universe, the sun, the moon, the stars and the planets - among them our near neighbours, Venus and Mars. Also featured are discussions on comets, asteroids and black holes, as well as eclipses, exoplanets and the mysterious, invisible substance known as 'dark matter'. Topping and tailing the collection are episodes dealing with the science of astronomy, examining Ptolemy's geocentric theory of the universe and the relationship between astronomy and the British Empire.

Hosted by veteran broadcaster Melvyn Bragg, with contributions from expert scholars and academics including Sir Martin Rees, John Gribbin, Carolin Crawford and Sir Roger Penrose, these captivating colloquies will inspire anyone with a sense of wonder and a thirst for knowledge.

Production credits

Presented by Melvyn Bragg

Produced by Natalia Fernandez, Thomas Morris, Simon Tillotson, Julia Johnson and Phil Tinline

First broadcast on BBC Radio 4 on the following dates:

Ptolemy and Ancient Astronomy 17 November 2011

The Multiverse 21 February 2008

The Universe's Origins 20 May 1999

The Universe's Shape 7 February 2002

The Age of the Universe 3 March 2011

Galaxies 29 June 2006

The Sun 10 July 2014

The Moon 3 November 2011

Eclipses 31 December 2020

The Planets 27 May 2004

Venus 27 December 2018

Mars 11 January 2007

Saturn 14 January 2016

The Kuiper Belt 2 March 2017

Exoplanets 3 October 2013

The Life of Stars 27 March 2003

The Death of Stars 9 June 2022

Black Holes 12 April 2001

Asteroids 3 November 2005

Comets 17 January 2013

The Cool Universe 6 May 2010

Dark Matter 12 March 2015

Dark Energy 17 March 2005

The Vacuum of Space 30 April 2009

Solar Wind 23 January 2020

Astronomy and Empire 4 May 2006