It doesn’t matter how long I studied astrophysics or spend time reading interesting articles about the Sun, planets or unexpectedly large black holes in small galaxies, I am always floored by the scale of the Solar System.
Next week I’m in London giving my first talk as part of my Defying Gravity lecture tour for the Institute of Physics. Well, technically it’s a dress rehearsal. Anyway, I’ve been preparing all of my demonstrations and learning my lines. The last demonstration I had to get together was a scale model of the Solar System. I am using it to help the audience get a sense of scale and an understanding of where we have explored so far. Not the most original idea, but I think it will be effective.
For my Solar System, I’m basing it around a yellow Pilates ball as the Sun. At that scale, the Earth is 7mm. The Pilates ball has a diameter of about 650mm. That’s an incredible difference! I know I see the Sun all the time, but it’s this bright disc in the sky that we’re not supposed to look at directly and it never looks that big (I know, I know, it’s far away!).
In this section of the lecture I’m going to show the audience Earth from different perspectives: the famous Moon rise image, the Pale Blue Dot and my favourite: Cassini’s accidently portrait of the Earth and Moon.
I think the combination of these things help to put us in our place. We’re small, but significant, things in a bigger environment and we shouldn’t take what we have for granted, especially when compared to the life of the universe, we exist in a blink of an eye.
So my suggestion for this cold Friday, is try to look up a bit more! There’s lots out there…
I have written a basic spreadsheet for modelling the sizes and distances of planets with respect to the Sun. This can be used when creating models of the Solar System. It is available to download here: Solar System Size and Distance. If you do use it, please leave a comment below telling me how.