Producer: MacMillan
Memory Required: 48K
Retail Price: £5.95
Author: JM Hargreaves

This is another pure educational program. It will not produce star maps as such but instead produces rather simple maps to demonstrate the shape and position of any one of 15 constellations which can be viewed under option One, which produces a slide show effect. The maps are annotated to name the important stars and to demonstrate how they form patterns. After the constellation has been plotted you are asked if you require any further information; answer Y and the lines of text appear at the bottom of the screen. Should the text refer to particular stars, then they will flash to make their position known, followed by an interesting fact or two, eg 'if Betelgeuse occupies the position of our sun, then it would reach beyond the orbit of earth and Mars'.

Option three gives access to a menu of 75 stars. Each one has a page showing which constellation it is in, the type of star it is and its distance in light years from the Sun. If any technical terms are used in the description you will find a cross reference to the glossary section accessed by Option Five. This option only holds explanations for ten technical names, but the explanations are useful.

Option Four accesses a quiz to test your knowledge on constellations and stars. The questions are not as searching as those in Stargazer. The graphics and writing have been designed to aid viewing, the colours chosen greatly enhance the clarity. The method of menu selection can be a little clumsy, again the programmers have not used the one touch system throughout and performing the same function on different pages, such as returning to the menu, will require different key presses depending on the mode you are in, this can make the package slightly more confusing to use. On the whole a useful package for getting the basics across to an audience.

Spacescan
Publisher: Macmillan
Memory: 48K
Price: £5.95

Astronomy
Publisher: Scisoft
Memory: 48K
Price: £10.00

The arrival of Halley's comet in our solar system has generated interest in astronomy.

Spacescan is a program designed to introduce you to star maps and the position of the constellations. Fifteen constellations are displayed with a map, named stars plus some information. Those maps can be printed out for observation. Another program, Starsearch, allows you to search through 75 heavenly bodies. There is also a quiz and a glossary.

Astronomy, by Scisoft, contains similar information but scattered across four programs. The information contained is more detailed and the graphics are not as good as Spacescan. Moon phases and Saturn draw are two facilities which could well have been left out, though the Ephemeris section could prove useful. Keen observers could use printouts to identify stars.

Both programs use database techniques but without the stunning graphics found in most astronomy books. As with a great deal of educational software the price seems just too high for what you receive.

MACHINE: Spectrum
Price: £5.95
FORMAT: cassette
PUBLISHER: MacMillan

Watch the skies this autumn and you'll see a spectacular sight. Halley's Comet is streaking across the heavens and will be close enough to be observed with the naked eye by the end of this year. It only comes around every 76 years - so don't miss it! While you're waiting for the comet to turn up, you could be observing other interesting objects in the skies - not just passing UFOs either. Our MSX expert, TOM SATO, who also used to study astronomy and often spent time overseeing observation work at the University of London Observatory in North London, now looks at the odd goings on in the night sky and some of the new astronomy software which can help you enjoy the wonders of the real universe...

There's no doubt that the arrival Halley's Comet will be one of the most spectacular celestial events of the decade.

This comet has punctuated our history every 76 years with awesome display. The earliest record of its appearance was in 87BC. For many centuries the great comet terrified people. It was blamed for famine, revolution, plague, and wars. Now we know better, but it was not until 1682 that astronomer, Edmond Halley discovered that the comet approaching that year was the very same one that had appeared in 1456, 1531 and 1607. He did some calculations and predicted that the comet would appear once again in the year 1758. When the comet returned on cue, it was named Halley's Comet to honour the astronomer!

Between November this year and March 1986, you too will be able to witness this great event. It will appear low in the western sky just after sunset. It will be more easily observed in the southern hemisphere but it should be visible to the naked eye in the skies above this country.

You'll also be able to watch it on television. The Americans, Russians, and Japanese are sending spacecraft to take a closer look at this fascinating object. The European Space Agency is also sending a probe, called Giotto (pronounced Jotto), using the Ariane launch rocket. The space craft Giotto is now being built by British Aerospace and will approach the comet as close as 300 miles to take TV pictures of the comet's surface.

Many astronomers now widely believe that comets are just huge snowballs containing rocks.

When they approach the Sun, the intense radiation evaporates the surface of the comet and gas and dust are blown away as a glowing plasma at an extremely high temperature. The solar wind, then carries this plasma away from the comet nucleus to form the "tail".

While you are waiting for the comet, you could still see some amazing sights in the night sky. It's good fun solving the mysteries of the universe and there are many fascinating phenomena you can observe simply by looking up.

If you go hill walking in midsummer, and if the air is clear enough and city lights far enough away, you can see many streaks of light appearing in the sky. Often the streaks are so faint that you might think that you were seeing things. However, what you are seeing is a typical meteor shower. A good meteor shower to see is the Perseids in mid-August. You'll see about 12 meteors per hour!

What are meteors? Well, they are dust particles smaller than a grain of sand floating about in space. When they come near to the Earth, the gravitational pull of the Earth attracts these grains and they start to fall.

When they reach the Earth's atmosphere, the particle starts to burn because of the friction. Most meteors just burn up in the upper atmosphere and rarely make it to the ground but every day the Earth is showered with these objects.

Occasionally, the Earth passes through a patch in space where there are a lot of these floating dust particles. It's thought that they are left over from passing comets. As comets whizz around the solar system, they gradually break up, and leave a dust trail behind them.

These dust particles tend to travel together and that's why there are streams of meteors which the Earth passes periodically.

Recently a number of software houses have realised the potential for astronomy software to cater for the growing interest in astronomy, as Halley's Comet approaches. Three astronomy programs have just been released which are now available for the BBC: Star Gazer by Century, Star Seeker by Mirrorsoft and Astronomy by BBC publications.

Star Gazer and Star Seeker are star map programs which show you what can be seen by the naked eye.

The Mirrorsoft Star Seeker program was devised by Dr Paul Philips University College London.

Star Seeker allows you to move the cursor to the position of a star and find out all the facts about it of which over 300 are covered. This package includes a program called Solar System which shows the position of the planets and also works out where Halley's Comet is. Most useful in the coming months.

Star Gazer is also a star mapping program but it includes a 100 page book astronomy written Heather Cooper, who is the current President of the British Astronomical Association.

If you would like to hear up-to-date news on astronomy, why not give British Telecom's Spaceline a ring. It is run by Dr David Whitehouse and updated every week. To hear the recording, phone (01) 246 8055.

Spectrum owners can look to the heavens using software packages like Starsphere from the aptly named Eclipse Software. Starsphere can plot 355 stars in 45 constellations and is menu driven. It gives a map of the entire night sky which can be rotated to show how the star patterns change with the passage of time.

Space Scan from MacMillan is an educational package. It won't give you star maps - but it will show you the shape and position of any one of 15 constellations. You also get a quiz option to test your knowledge.

Eaglesoft's The Solar System is a sort of Hitch Hiker's Guide to the objects "captured by the gravity of the Sun". The menu allows you to select various text information about various subjects - combined with graphic illustrations.