When you look at pictures of stars and galaxies, it's hard to tell how
big they are. Sometimes the caption will say that the photo covers
area of the full moon, but some photos are of much smaller areas,
it would be nice to have a visual comparison in any case. (Arc-
I propose a standard outline of the moon, or rather a set of standard
outlines, scaled and scalable. These can be incorporated into any
photograph without taking up much of the image. In these digital
it will only take a few seconds to do.
The first is a simple complete circle. It can be filled in as a black or
white spot, or just used as an outline.
As the apparent size of the moon increases, the outline becomes an
arc. The line of the arc can either be drawn across part of the
or used on one side as a cropping tool.
As the arc straightens further with increasing size, the noticable-
affect would be lost. But---and here is the gist of this idea---
mountains appear on the outline of the moon in finer scales
The first feature on the arc will be three humps representing Tycho
crater's profile, as the rim and center peak. Zooming in on the
center peak brings out the complex, then the highest peak, then
details, the very top, a lunar lander, an astronaut, his religion, and
on down to molecular scale if ever needed.
The current need, as best I can tell, is still mostly in the
arc scale. The Hubble Deep-Field image is about the size of Tycho
crater, I think.
(On my touch-screen, here, it's all hopeless.)