First:isoparix wrote: ↑Wed Apr 29, 2020 9:34 am

I still want to know how you pack eight Jupiters stably, in between Earth and Mercury....

**there are only 2 Saturn/Jupiters**(on the outside).

And it probably helps that

**none**of the planets lies in the

**"Kirkwood Gaps" of any other (larger) outer planet:**

*dreaded 3:1 or 2:1 resonant*Code: Select all

```
The Kepler-90 planetary system
(AU) Orbital period (days) Radius
...............................................................................
b 0.074 ± 0.016 7.008151 day 1.31 R⊕
...............................................................................
2:1 7.22 day i resonant "Kirkwood Gap"
...............................................................................
c 0.089 ± 0.012 8.719375 day 1.18 R⊕
i 0.107 ± 0.03 14.44912 day 1.32 R⊕
...............................................................................
3:1 19.91 day d resonant "Kirkwood Gap"
2:1 29.87 day d resonant "Kirkwood Gap"
3:1 30.65 day e resonant "Kirkwood Gap"
3:1 41.64 day f resonant "Kirkwood Gap"
2:1 45.57 day e resonant "Kirkwood Gap"
...............................................................................
d 0.32 ± 0.05 59.73667 day 2.88 R⊕
...............................................................................
2:1 62.46 day f resonant "Kirkwood Gap"
3:1 70.20 day g resonant "Kirkwood Gap"
...............................................................................
e 0.42 ± 0.06 91.93913 day 2.67 R⊕
...............................................................................
2:1 105.30 day g resonant "Kirkwood Gap"
3:1 110.53 day h resonant "Kirkwood Gap"
...............................................................................
f 0.48 ± 0.09 124.9144 day 2.89 R⊕
...............................................................................
2:1 165.80 day h resonant "Kirkwood Gap"
...............................................................................
g 0.71 ± 0.08 210.6070 day 8.13 R⊕
h 1.01 ± 0.11 331.6006 day 11.32 R⊕
```

https://arxiv.org/abs/1310.5912 wrote:

A Hill stability test and an orbital integration of the system shows that the system is stable.