Stopping Is Hard

Here I am, cracking on with my goal of a to-scale diagram of the Sun and Mercury within an A0 size sheet. It’s not too hard to scale the Sun and Mercury relative to each other. But placing them relative to one another is a different matter. And relative to what?

This is where the difference between the ecliptic and the invariable plane come into play. Even though most use the ecliptic that’s because we view from Earth. But we’re looking from a perspective of space inwards – so the invariable plane it is!

That means I need to include the angle of Mercury to the invariable plane. Its orbit is elliptical, so I also need to account for its aphelion and perihelion, whilst placing it at the mid-point. Plus show its angle of rotation (and direction). Details matter!

I’m done. But now I’m energized. How far can I take this? After all, could I do the same thing and squeeze Venus into another sheet? Yes, it turns out I can. Let’s add that into the mix and double the size. It’s still a reasonable prospect. And the relatively flat angles mean it isn’t too high (just wide).

But if I’ve got Venus, how can I not include Earth? And the Moon. After all, it’s not much smaller than Mercury. A quick calculation and I confirm it’s within my minimum visible size – we add both into the mix. Now we’re three times our original width.

It now feels a shame to miss out Mars – especially when we might inspire travelers to set foot on the planet in future. Now we’ve quadrupled the width (still without increasing the height).

I might have overdone it at this point. Can it still fit within a normal wall in a normal room? It might just, although at around 4 metres long, it’s much bigger than I had set out to create. But nothing stops someone from slicing it in half or placing it on two walls. Plus the inner terrestrial planets are a nice group to have in one visual. Sorted.

It’s confirmed. I’m doing the design for the inner Solar System at a scale of 60bn:1!