Secrets of the universe: how we discovered the cosmos

The seven planets : wandering stars

Stars and constellations : our human link with the ice age

The milky way : path of the gods, souls and pilgrims

The shape of the Earth : our planet, a flattened sphere

The southern constellations : hidden stars revealed by the tilting earth

The sun : at the centre of the solar system

Comets : disasters, sun-grazers and the 'lady's comet'

The satellites of Jupiter : Galileo shatters the crystal spheres

The phases of Venus : revealing the shape of the Copernican system

Uranus : William Herschel discovers the first new planet

Neptune : the planet discovered by the pen

Asteroids : remnants of the early solar system

Pluto : a planet deliberately sought, but not a planet and discovered by accident

The Kuiper belt : the frontier of the solar system

Meteors and meteorites : the sky is falling!

Meteor showers : in the middle of the night, stars fell like rain

The Earth's magnetosphere : our defence against the sun

Comets : sandbanks or dirty snowballs?

The Earth's climate, the seasons and the weather : astronomical cycles

Asteroid impacts on the Earth : the true origin of craters on Earth

Origin of the moon : neither daughter nor sister of the Earth

Mercury : the late heavy bombardment

The greenhouse effect : Venus and the Earth

Mars : the dying planet

Water on Mars and Europa : evidence for extraterrestrial life?

Volcanoes on Io : Linda Morabito makes a chance discovery

Saturn and the gas giant planets : lords of the rings

Helium : the cosmic element

Gravitation : determinism and chaos

Relativity : the nature of space and time

Radio waves : a new window on the universe

X-rays from space : the energetic universe

Variable stars : discovery of star systems

Sirius B and white dwarfs : discovery of stellar cinders

Neutron stars and pulsars : lighthouse stars

Black holes : a solution looking for a problem

Distances of the stars : the radiance of a star that was shining years ago

The discovery of our galaxy : stars in an island universe

Interstellar nebulae : stars, molecules, dust and gas

Star clusters : nebulae resolved

Supernovae : origins of the stardust from which we are made

Supernova 1987a : the whisper and the vision

Cepheid variable stars : stars' heartbeats that measure the universe

Exoplanets : other worlds beyond ours

The energy of the sun and stars : discovery of nuclear fusion

The origin of the elements : making star stuff

Inside the sun : whispers and rings

The crab nebula : a supernova remnant

Planetary nebulae : looking into secret places

The origin of the stars and the planets : the solar nebula and proplyds

Interstellar dust : curtains of diamonds and graphite

Hydrogen : the most abundant element in the universe

Galaxies : ellipticals, spirals and mergers

Magellanic clouds : our neighbour galaxies

Quasars : active galaxies

Supermassive black holes : monsters at the centres of galaxies

The black hole in our galaxy : a dormant monster

Gamma-ray bursters : the biggest bangs since the big bang

The evolving universe : the past, the present and the future

The cosmic microwave background : the after-glow of the big bang

Darkness at night : the missing galaxies

Dark matter : a dark secret to uncover

Dark energy : on the threshold of a profound discovery

Gravitational waves : whispers of neutron stars and the big bang

Life in the universe : are we alone?