Patrick Moore looks at the new and quite unexpected developments in our understanding of Beta Pictoris and Van Biesbroeck 8-two very different stars, but both associated with faint companions.

The Anglo-Australian

Halley's Comet is now approaching the Sun and the Earth. Patrick Moore explains when and where to look for the comet, and describes the various investigations which are to be carried out both from the Earth and by space-craft.

The Infra-Red Astronomical Satellite, IRAS, operated for most of 1983 and provided important information about subjects ranging from the dusty tails of comets to star formation in remote galaxies. Patrick Moore talks to Dr Jim Emerson of Queen Mary College about these new results and their significance.

The moon is a world of mountains, craters, valleys, peaks and huge waterless seas. Of special interest are the cracklike features known as rills, which are unlike anything we find on earth. Patrick Moore talks about them to Dr Lionel Wilson of the University of Lancaster, who has been making a careful study of these remarkable lunar features.

During its voyage to Jupiter, the American Galileo probe will survey a small and interesting world, the asteroid Amphitrite - one of the swarm of minor planets moving round the sun between the orbits of Mars and Jupiter. Patrick Moore talks about the Amphitrite encounter, and about the whole swarm of these little worlds which were once referred to by a German astronomer as 'vermin of the skies'.

How do you find your way around the sky? It is not difficult; the constellation patterns are easy enough to make out.

Infra-red radiation, often termed 'heat', is an important part of the total range of wavelengths now being studied by astronomers. Striking results have been obtained at the Siding Spring Observatory in Australia. In this programme Patrick Moore talks to Dr David Allen from Siding Spring and shows some of the spectacular new pictures.

Mizar, the second star in the 'handle' of the Plough, has a faint companion, Alcor, easily visible with the naked eye. Use a telescope and Mizar is seen to be double; and the brighter member is again double. Patrick Moore talks about Mizar and speculates as to the view from a planet moving in this system.

Many amateur astronomers have large telescopes but Ron Arbour 's observatory, near Winchester, is exceptional; his 16-inch reflector is computer controlled and is programmed to hunt automatically for stellar explosions far across the universe. Patrick Moore visits the observatory to talk to Ron Arbour about his telescope and about his plans for photographing Halley's Comet later this year; during the programme he attempts to get a photograph of the comet specially for The Sky at Night.

How large is the universe? Astronomers measure the distances of very remote objects by using spectroscopes, but today there are some doubts as to whether the measurements are reliable. Two star-systems in the constellation of the Fishes appear to give very confusing results. Patrick Moore talks to Iain Nicolson about these new results and what they may mean.

Halley's Comet is now back and can be seen with binoculars, and should be visible with the naked eye next month. Patrick Moore talks to Douglas Arnold (photographing the comet);

The science of astronomy is thousands of years old. Yet only in the last few decades have astronomers made discoveries that have proved the old theories wrong. Venus has no water - Mars has no canals - Man did not sink without trace into the moon's dust. Patrick Moore tells the stories of these old theories, and explains how, because of one mistake, the size of the universe was doubled.