01: Align your finderscope
Make sure the finderscope on your telescope is aligned with the main scope. This will help you more easily find the Moon in the eyepiece and also ‘zero in’ on interesting parts of the surface.
02: Improve your disc viewing
Use a low-power eyepiece to start with for your observations. This will help you see the whole disc and orientate yourself with the view. You can increase the magnification later.
03: Reduce glare
A Moon filter is really helpful to dim down the brightness of the Moon, especially when it is near ‘full’. This is a grey (neutral density) filter which screws into the telescope’s eyepiece.
04: Use your motor drive
If your telescope has a motor drive, make sure that you have it switched on. The Moon will appear to move swiftly across the field of view and especially at higher magnifications.
05: Find the terminator
Direct your scope on to the ‘terminator’, the line dividing the light and dark areas of the Moon. This is the most interesting place to look. Look out for sunlight catching crater rims and mountains.
06: Locate the lunar highlands
Another very interesting area to explore with your telescope is the
‘highlands’, especially in the northern and southern regions, as they show up well due to shadows, even near full Moon.
What to observe
94 Astronomy for Beginners
I
t’s sometimes hard to remember that when you see all those tiny twinkling points of light up in the night sky, that each one of them is a raging nuclear inferno. To appreciate this for yourself, you only need look at the Sun. Of course it’s so powerful, you need to take great care as it is very easy to blind yourself. If you are in the slightest bit doubtful about what you are doing, then don’t do it. But if you are careful and follow the guidelines given here, you will find that observing the Sun is both fun and an endless source of fascination.The Sun is constantly changing and darker areas called ‘sunspots’ move across its disc over the course of a few days. They come and go in a cycle of roughly 11 years. Very occasionally you might see a brighter region on the disc. These are known as ‘faculae’ and are associated with flares where the Sun blows out very hot material into space.
The safest way to see the surface of the Sun or the ‘photosphere’, to give it its correct name, is to project the disc using a small telescope and two cardboard squares. The first square fitted around the telescope tube casts a shadow on the second so you can see the projected disc of the Sun clearly. You point the scope at the Sun by watching the shadow cast by
the ’scope; when the shadow is smallest is when the telescope should be pointing in the right direction. Never attempt to look through the telescope! Focus the telescope in the usual way to get a sharp image of any sunspots. The best time to view the Sun is early to mid-morning or late afternoon. The heat of midday can spoil the view, making the atmosphere turbulent and causing images to wobble.
You can get special solar filters to use with your telescope, but only buy these from reputable dealers. These fit over the front aperture of your telescope and are made from either specially coated glass or from a special metallised film called ‘astro- solar film’. This looks a little like aluminium foil, but is designed to block out dangerous radiation such as ultraviolet. Always check such filters before each and every use. Hold them up to a light bulb and check for any scuffs or pinholes which could let sunlight through. If these are present, discard the filter. If you find your telescope supplied with a small filter which
is supposed to fit on to the eyepiece, do not use it! These are very dangerous as they can shatter in the heat thereby exposing your eye to the full force of the Sun’s energy.
There is a new type of filter available now called a ‘hydrogen-alpha filter’ often coming fitted into special telescopes designed for solar viewing. These are amazing instruments which will show you otherwise impossible to see features. With such a telescope or filter you can see ‘prominences’, huge fountains of material standing out from the surface of the Sun and also ‘filaments’, which look like dark lines etched on the disc. These are in fact prominences seen from above. The disc of the Sun looks mottled through this type of filter as well. Here you are looking at ‘cells’ of material thousands of miles across, bubbling up from the lower layers of our star. All in all, the Sun is an amazing, dynamic object and well worth your time as long as you’re careful. After all, it’s astronomy in the warm!