In the Greek island of Samos, situated on the eastern border of Greece and Turkey, barely separated by a narrow stretch of sea, there lived a man called Aristarchus in the third century BC. He was a brilliant observer of skies and drew up a catalogue of more than 1,000 stars according to their respective luminosities.

He divided them up in 100 grades of magnitude, allotting the magnitude of one (1) to the brightest stars, and number six to those stars that are barely visible to the naked eye, i.e. at the limit of human vision. The other stars, or objects fell in-between, in order of their luminosity, taking recourse to decimals wherever necessary. Any object brighter than 1 was given their magnitude in minus (minuses), such as that of the sun, or moon. His method of brightness or luminosity, called magnitude has survived to this very day.

Another scientist of great consequence was the Arab, Al-Sufi whose work formed the basis of science for several centuries and was taught in European universities for a long time. But, unfortunately, it is the Western bias which has confined the scientific and social achievements to Greeks and the other Western scientists, and not to the Arabs even where it rightfully belongs.

Just to give you an idea of magnitudes of various objects a list of these is provided below:

Sun -26.5 (never look at the sun); Moon (full) -12.6; Venus -4.4 (when brightest); Jupiter -2.5; Sirius -1.4; Rigel + 0.0; Polaris + 2.0;

naked eye limit +6.0 (a lot of stars are visible beyond naked eye limit but only with a reasonably powerful binocular, or still better, with a telescope).

Now it is possible for you to go out, explore the night sky, armed with a reasonably sound knowledge of stars and, in some cases, their magnitude, and work out for your self their approximate magnitude. Never mind if it is not accurate. In the voyage of discovery, conjecture or estimation often lead to unexpected success; and when that happens, it is truly remarkable!

In the case of comets, you already know that they are not visible when at farthest from the sun. In the course of their long journey away from the sun, there comes a point when they make a U-turn towards the sun and gain in speed with the passage of time. At first they are not visible to us so there is no question of any magnitude. But there comes a point where the first, faintest of faint blob or a hazy patch appears to the discerning astronomer and he cries "Eureka!" That can be said to be a sixth magnitude object. From hereon it grows in size and some weeks or months, later develops into a clearly visible object at night, or sometimes even during daytime. In that case, it also 'grows' in magnitude. Some comets, besides being seen at night have also been seen in daytime. They are so bright! I have seen one named Ikeya-Saki way back in 1964 when I was still in school, and saw it many days in succession!

You may like to know that of the hundreds of comets most have been discovered by amateur astronomers. So you need not feel disheartened, or left out. Instead get yourself a small telescope and start scanning the skies for objects (how about a telescope for the next birthday). At first it may not bear easy result, but eventually it will. Remember that perseverance rewards, and rewards well. In due course we shall not only talk at length about comets but also how to look for them. And remember also any comet discovered by an amateur is named after that person, male or female, and internationally acknowledged as such. So, be the first Pakistani to give your beautiful country a soft image through astronomy.

Remember also, that a telescope is not the most essential gear for an astronomer. It is the will to stay up, be outdoors for a couple of hours or so and look in the right region in the sky. For a beginner, the constellation Orion is probably the best region to hunt. Look for the lovely nebula, just below the belt (I have seen it with naked eye). Or, constellation Surrayah nearby. The two bright stars of constellation Gemini (Pollux and Castor) are not very far to seek; the bright star called, Aldeberan, being the flag star of constellation Taurus, the Bull, is nearby, crying for attention.

How can you ever miss the galaxy, Andromeda, which is twice the size of our own? It is a spiral galaxy like the Milky Way and, interestingly, 2.2 million light years away. It is so-called because it lies in the constellation of the same name, i.e. Andromeda.

And then, the meandering, twisting and turning arm of the Milky Way. These wonders and more all in a night's work! Those naughty shooting stars called meteors being the icing on the cake!