Keeping records

Whether you are a casual star-gazer or a dedicated observer, it is a good idea to record any observations you make. There are different ways to do this. One is by means of a specially drawnup sheet, which details all the relevant information of your sighting. Another is to keep a log book - especially if you are a regular observer. Whichever method is chosen, record as many details as possible while you are at the telescope; add any finishing touches while they are still fresh in your mind.

For those with a flair for drawing, a good sketch of the cloud belts of Jupiter, a lunar crater or the polar caps of Mars can equal or better a photographic record. Cameras can sometimes fail to capture subtle tones on planetary surfaces that the human eye can pick up quite clearly.

To make matters easier, it is advisable to prepare, on paper, blank discs for planetary observations. A good size is about a 5-cm (2-in) diameter, but those for Mercury could be smaller, while the opposite applies to Saturnto accommodate the ring system. Solar observers should keep their disc drawings to a maximum of about 15 cm (6 in). When preparing discs for Jupiter, bear in mind that the planet has considerable polar flattening. Sketches of the lunar surface will have their dimensions governed by the size of the feature being drawn.

Drawing comets is something of an art in itself and practice is necessary before you can expect good results. Once seen, the comets' appearance as diffuse patches, rather than points of light, will give them away as they move against the fixed stars.

Whatever type of observation you make, try to record exactly what you see, rather than what you would like to see. Record, too, the date and time of any observations and also the clarity of the sky. The more these rules are adhered to, the more valuable your efforts will prove to be.
 
Antoniadi scale of seeing conditions
  1. Perfect seeing, without a quiver
  2. Slight undulations, with moments of calm lasting several seconds
  3. Moderate seeing, with large air tremors
  4. Poor seeing, with constant troublesome undulations
  5. Bad seeing, scarcely allowing the making of a rough sketch
Seeing in this context is an estimate of the steadiness of the image. The scale, above, is universal, and it will help when comparing observations of the same object made from different sites and under different conditions.

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Record cards are vital for the serious observer. Their standard format and layout ensure that the same type of information is always recorded. This is particularly important when tracking some of the more transient planetary features.
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Templates, such as those for Saturn, above, and the Sun, right, can save much time and effort Once drawn, attention can be concentrated on any surface or atmospheric changes.
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