The space probe Cassini has been sending home fantastic pictures of Saturn and its satellites since 2004, and its mission has been extended twice. Its website has a wealth of images and some interesting material for teachers and astronomy fans.

What's the difference between a meteor, a meteorite and a meteoroid? Is one of them the same as a shooting star? And what about asteroids and planetoids - which one is a minor planet? If any of these terms have puzzled you, here is a guide to help you out.

Why is the Illuminations Planetarium unique? It's the only one that sails the seas. Purpose-built as part of a theater on board Cunard Liner Queen Mary 2, it shows astronomy films, and on some voyages, astronomers from the Royal Astronomical Society in London use it to present the night sky.

Henrietta Leavitt isn't a well known name, but a century ago she made one of the most important discoveries of 20th century astronomy. Previously, astronomers could only measure distances up to 100 light years, but her work extended that to 10 million light years.

High in the sky, circling the north celestial pole are the distinctive stars of Cassiopeia, the boastful queen who nearly destroyed her kingdom. The Milky Way runs through the constellation and it's full of star clusters, galaxies and evidence of the life cycles of stars.

Planet Earth presents a grand international sporting spectacular every four years, the Olympic Games. Even if you're not fond of sports, it's a majestic pageant and a set of unfolding dramas that a scriptwriter couldn't hope to emulate. Here is my astronomical tribute to this magnificent saga.

From ancient times to the present fifteen Solar System objects have been called planets. But there are only eight planets now. Find out what happened to the other eight and how the planets got their names.

A dwarf planet so far away that the Sun would look like a exceptionally bright star, so cold that its atmosphere is frozen for most of its year. This is Pluto, former planet, and now the gateway to the Kuiper Belt.

An ancient Greek tale of pride and passion is played out across the sky, involving five constellations including Cepheus the king. In Cepheus there are stars being born and stars at the end of their lives, including those which will die in a blaze of glory.

Can sound travel in space? The short answer is no, but it's not so simple. We can't hear the sound waves, but the Sun produces them. And then there's the black hole that astronomers have detected endlessly singing a B-flat over tens of thousands of light years.