<p>&quot;While e passes very near d&quot;</p>
<p>No, planets should not pass very near each other, for then pertubations between the planets will make the system unstable. It doesn't matter what plane the planets orbit in, the main thing to do to create a stable system is to keep the planets away from each other.</p>
<p>For the same reason &quot;b, c, and d ...  are always in the habitable zone.&quot; is also problematic, the usual orbital resonance is 1:2:4 and this gives a wide spread of distances, it is unlikely that all three can fit in the habitable zone without some flexible interpretation of what &quot;habitable&quot; means (for example &quot;habitable, but only under an ice sheet&quot;</p>

CC BY-SA 4.0
2024-09-28T21:18:01.757Z
2024-09-28T21:18:01.757Z
James K
<p>Say, hypothetically (these planets do not exist), you have two terrestrial planets (b,c), one gas dwarf(d), and one gas giant(e) all orbit the habitable zone in some manner.</p>
<p>b, c, and d all have an orbital resonance, which cause an eccentricity of 0.04. They are always in the habitable zone.</p>
<p>e has a very high eccentricity of 0.93, causing it to go on the outer fringe of the habitable zone, then go out into the frigid outer solar system. While e passes very near d, it does not orbit its star on the same plane as d.</p>
<p>Let's pretend that this star is an M-type star, around 0.45 solar masses.</p>
<p>I want to know if this is theoretically possible.</p>

CC BY-SA 4.0
2024-09-28T21:19:15.417Z
After reading this the answer probably is yes. I am not so sure about the different eccentricities though. https://planetplanet.net/2017/05/03/the-ultimate-engineered-solar-system/
The Rocket fan
CC BY-SA 4.0
2024-09-29T09:45:12.157Z
Cross-posted to https://worldbuilding.stackexchange.com/q/261983
PM 2Ring
<gas-giants><terrestrial-planets>
Is this possible?
Anonymous
# Is this possible?

(Asked by: username_0 on 2024-09-28)

Say, hypothetically (these planets do not exist), you have two terrestrial planets (b,c), one gas dwarf(d), and one gas giant(e) all orbit the habitable zone in some manner.

b, c, and d all have an orbital resonance, which cause an eccentricity of 0.04. They are always in the habitable zone.

e has a very high eccentricity of 0.93, causing it to go on the outer fringe of the habitable zone, then go out into the frigid outer solar system. While e passes very near d, it does not orbit its star on the same plane as d.

Let's pretend that this star is an M-type star, around 0.45 solar masses.

I want to know if this is theoretically possible.

**Tags:** gas-giants, terrestrial-planets

> **Comments:**
> **username_1**: After reading this the answer probably is yes. I am not so sure about the different eccentricities though. https://planetplanet.net/2017/05/03/the-ultimate-engineered-solar-system/  
> **username_2**: Cross-posted to https://worldbuilding.stackexchange.com/q/261983  

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## 1 answers

### Answer by username_3 on 2024-09-28. Score: 5

"While e passes very near d"

No, planets should not pass very near each other, for then pertubations between the planets will make the system unstable. It doesn't matter what plane the planets orbit in, the main thing to do to create a stable system is to keep the planets away from each other.

For the same reason "b, c, and d ... are always in the habitable zone." is also problematic, the usual orbital resonance is 1:2:4 and this gives a wide spread of distances, it is unlikely that all three can fit in the habitable zone without some flexible interpretation of what "habitable" means (for example "habitable, but only under an ice sheet"


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