It's been a while since I posted anything here so to rectify that read on to discover why the moon is like Scarlett Johansson and along the way Galileo, Buzz Aldrin, ET and a drunken zombie all get a mention too.

Any astronomer with any degree of experience will have a list of things they really want to see. Many, for example will have no doubt fantasised about seeing Betelgeuse going supernova perhaps while they happened to be looking at it. Or it might be watching a comet perform a death plunge into Jupiter and observing the resulting scars in its atmosphere, which would no doubt be an awesome sight to see. Maybe some people even secretly hope to discover an asteroid on a collision course with Earth that is big enough to send us the way of the dinosaurs. But when you first began your adventure in astronomy your list will be slightly more prosaic.

For a lot of people their number one must see is Saturn in all its ringed glory. No matter how many times you see it, it is simply spectacular. Or perhaps it is Jupiter and its four largest moons that pretty much look the same today as they did when Galileo first observed them with his telescope four hundred years ago. And then of course there are old favourites like the Andromeda galaxy, the Orion nebula or the slightly disappointing Mars. For some it is simply going to a dark sky site and seeing more stars than you believed existed and being awed by the sight of the Milky way arching overhead. These are all worthy objects that appear in any astronomers top ten sights to see in the night sky. One thing a lot of people don’t have down as a priority though is the moon.

This is surprising since it’s the most obvious thing people recognise in the night sky but also understandable for the very same reason. Everyone is so used to seeing it mooning at them all night and sometimes during the day that they feel they’ve seen it all before. Yes, people always marvel at the way it looks bigger when it’s closer to the horizon and everyone likes that bit in ET when Elliot and co. fly in front of a huge full moon, but give someone a telescope and it’s not usually the first thing they look at. There is some truth in thinking that the moon is so familiar that there is nothing new to see. Many features for example can be picked out with the naked eye and most people are aware that we only ever see one side of it so it is a bit samey from that point of view. But, and it is a big but, when you do finally swing your telescope around to the Moon you will stand in slack jawed amazement and say the only word your brain can push out of your mouth at such times which is ‘Wow!’.

You might ask how is it possible to be so awed by something that appears so ordinary but the answer to that question can be most concisely summed up as “Magnificent desolation”. Those were the words of Buzz Aldrin when he hopped off the lunar lander and had a look around and when you put a high magnification eyepiece into your telescope and point it moonward you’ll know exactly what he meant. You will be quite simply astonished and wonder how you failed to realise what a beauty of an object it is. It is the astronomical equivalent of barely noticing the girl next door for several years and then one day bumping into her at the bus stop and realising she’s Scarlett Johansson. And in much the same way you will then spend a great deal of time late at night in your garden with some binoculars.

The particularly brilliant thing about the moon though is the level of detail you can see. Let’s face it many objects that we spend time looking at can best be described as fuzzy and indistinct. Even the planets in the solar system reveal very little detail to the visual observer and when they do you are talking of features hundreds if not thousands of miles in size. The moon is different. Here we’re talking objects perhaps as small as a kilometre that can be resolved by even a modest telescope. Regardless of the power of your equipment though you will spend hours peering through your telescope discovering little gems of detail in the many craters and mountains you will see. You’ll crank up the magnification to ridiculous levels which you can get away with when the thing you’re looking at is so close and so bright. When the moon is full and with just the right eye piece you’ll be able to fill your field of view with the entire moon and it looks brilliant.

The only down side to staring at the moon for the first time is that you probably won’t have the benefit of a moon filter and you will discover the brightness of la luna has left you temporarily blind in one eye. I’ve never tried looking at the moon through binoculars but presumably doing so leaves you stumbling around like a drunken zombie until the effect wears off. Luckily, if you’re the owner of a Newtonian reflector, particularly the Skywatcher variety there is a solution of sorts that comes free with your telescope. It could be described as the end cap, end cap.

To explain, here's a picture of the end cap of my telescope, note the small end cap removed from the much larger one.

Many people puzzle over the intended use of this little hole but one thing you can do is use it to cut down the glare when observing the moon. You simply leave the large end cap in place and remove the small one and voila light entering your telescope is reduced substantially and you can thus observe the moon without the usual temporary blindness.

However the problem comes when you've finished your lunar observing and decide to have one more look at Jupiter before you pack up. ‘Hmm, that's funny’ you'll think. It’s very dark and really lacking detail and it looked brilliant earlier. You may swap out an eyepiece, check you've not got a filter on and in desperation you'll fiddle around with things that can't possibly affect your view. Bewildered you'll start to pack up your stuff and when you go to take the dew shield off the end of your telescope you'll notice the big end cap still in place with just the little hole open to the universe. Happily it will be dark enough to cover your embarrassment and you can pretend that you knew it was there all the time.