# Titus-Bode rule

**URL:** <https://boards.straightdope.com/t/titus-bode-rule/348554>\
**Category:** Factual Questions\
**Created:** [March 16, 2006, 2:08am UTC](https://boards.straightdope.com/t/titus-bode-rule/348554 "2006-03-16T02:08:59Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Lumpy](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lumpy/32/446_2.png) [@Lumpy](https://boards.straightdope.com/u/Lumpy)\
**Post date:** [March 16, 2006, 2:08am UTC](https://boards.straightdope.com/t/titus-bode-rule/348554/1 "2006-03-16T02:08:59Z")

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Wikipedia has a very interesting entry on the semi-regular spacing of the planets. I thought of a question that wasn’t covered though. The article did point out that the spacing shouldn’t necessarily be geocentric (Earth = 1.00) and even postulated an Mercury Unit (MU) to replace the AU. But wouldn’t a much better candidate be Jupiter? The most massive, most gravitationally influential of the planets? Does a JU give a better fit for the Titus-Bode rule?

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**Author:** ![Bytegeist](https://avatars.discourse-cdn.com/v4/letter/b/9dc877/32.png) [@Bytegeist](https://boards.straightdope.com/u/Bytegeist)\
**Post date:** [March 16, 2006, 4:15am UTC](https://boards.straightdope.com/t/titus-bode-rule/348554/2 "2006-03-16T04:15:26Z")

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The mathematical relationship expressed in the “Law” will be essentially the same, no matter the distance unit, only with different constants. If you wanted everything in Jupiter-AUs instead, you’d divide the T-B formula by 5.2. If you prefer Mercury-AUs, then you’d multiply it by 2.5.

If you picked one-tenth of an AU as your preferred unit, then all the distances will come out as nice round integers — assuming you like that sort of thing.

Personally I find it easier to just memorize the planets’ approximate distances in AU. No need for the “Law”, which as far as I know has no physical basis.