All About Space Astronomer Book - 2014 UK

[15] Part of a massive mosaic built from 62 separate but overlapping images of the Moon

taken through a 14-inch SCT using a high-frame-rate camera at prime focus. The circular

sea visible in this shot is Mare Crisium.

of these filters can give the camera a steadier view. If the seeing is already
very good, a green imaging filter can be used. The wavelength of green being
shorter than red, this can produce even sharper end results.
For the best results, it’s essential to take your telescope outside several
hours before you begin your imaging run. This will allow the main optical
tube time to cool, reducing the possibility of unwanted internal air currents.
A 12V camping hairdryer attached to a suitable 12V battery source can be
used to keep dew and moisture at bay from optical surfaces if this becomes
a problem.

Lunar Mosaics
A typical high-frame-rate camera will have a relatively small imaging chip
compared to a general photographic camera. For the fastest-rate cameras,

14

15

Our friendly Moon

image sizes of 640 x 480 aren’t uncommon and, coupled to a telescope, the

area imaged can be quite small. Larger shots can be created by combining

smaller images together in what’s known as a lunar mosaic. The easiest

way to create a mosaic is to keep the camera settings fixed and methodically

image sections of the lunar surface, ensuring you have large overlaps. The

resulting captures must then be processed using a registration/stacking

program as described above, ensuring, once again, that the settings used are

consistent for all captures.

Using a layer-based graphics editor, the first image is loaded and defined

as the reference. The canvas size of the image – the amount of working

space around it – needs to be increased to accommodate the other sections.

The second image is loaded as a new layer and nudged into position so that

its overlapping features align with the reference image. A gentle 10% eraser

tool can be used to remove the straight edges of the upper layer to assist the

blend. This process is then carefully repeated for the other sections until the

mosaic is completed.

For those who wish to take an easier path, mosaic composition soware

can automate the process. An example of such soware is the MicroSo

Image Composition Editor (ICE) which, at the time of writing, is available to

download and use free.

Summary

This may be a very rudimentary description of our friendly Moon but we hope

it will suffice for the moment. We must always remember, it is the only world

away from the Earth we have been able to visit. It would be perfectly possible

to set up a permanent lunar base. The problem is with finance and political

will. As long as mankind is intent on spending money on war rather than

progress, the outlook appears rather gloomy! Meanwhile, the Moon awaits

us and will not go away. In the future the Solar System might have two

inhabited worlds rather than only one.

[12] Cracks cover the floor

of crater Gassendi.

[13] The brightest crater on

the earthward side of the

Moon – crater Aristarchus.

[14] Hadley Rille imaged

with a 14-inch SCT using

a high-frame-rate

camera fitted with a red

imaging filter.