Scale solar system presentation slide, a provisional version for you to review

Posted by Emily Lakdawalla

2011/09/15 02:18 CDT

Topics: scale comparisons

I'm preparing a talk for the Pacific Astronomy and Telescope Show here in Pasadena on Sunday afternoon at 1:45. I have spent the morning putting together a slide that I have long wanted to have for presentations. It includes all the big stuff in the solar system (everything bigger than 400 km across, making Mimas the smallest thing on it) to scale, using nice images with approximately correct color and rotated so that they all appear to be lit from the same direction. This means that some of the bodies are sideways or upside down, but I don't have a problem with that because "sideways" and "upside down" are just arbitrary conventions anyway.

With this many objects included on one slide, I'm sure I have made at least one error in scaling an image or ordering some satellites or something, so I'm putting a provisional version of the slide out here for your review. Here it is:

© 2011 Emily Lakdawalla, the Planetary Society. Images from NASA / JPL & JHUAPL missions, processed by Björn Jónsson, Mattias Malmer, Ted Stryk, & Gordan Ugarkovic. TNO art by NASA, ESA, and A. Feild (STScI)

Scale solar system presentation slide

A view of the largest objects in the solar system (other than the Sun), to scale with each other, everything larger than 400 kilometers in diameter, except that there are only eight trans-Neptunian objects standing in for lots that probably are larger than that.

One inaccuracy that I know about already: there are not enough trans-Neptunian objects to represent everything larger than 400 kilometers that's known to exist. Mike Brown recently posted a table listing more than 200 objects that probably or possibly are bigger than this -- there's a significant amount of uncertainty, of course, but statistically speaking it should be fairly representative. If I have time before my talk Sunday I'll have to add in more of those things!

Anyway, I'm asking eagle-eyed readers to tell me if there's anything wrong here, either by email or in the comments. Once I've got a version that I'm pretty sure is accurate, I'll post it in nice high resolution so that others can use it in their own presentations.

EDIT: Main inaccuracies pointed out so far are the order of Proteus and Triton. No, Jupiter isn't too small. Also, I initially said there were 45 objects probably bigger than 400 km in the Kuiper belt. That was out of date; it's more than 200 now.