Could advanced alien species rearrange the planets in their systems to leave a lasting message of their existence?!?
While in general the presence of the giant planets reduces the relative habitability compared to a system with just an exo-Earth, there are some cases where the giant planets make the system "ultra-habitable":
A couple trends we saw:
• Mass of the giant planets ↑, relative habitability ↓
• Very low relative habitability when the giant planets are in the habitable zone
• Eccentricity of the giant planets ↑, relative habitability ↓
• Secular resonances can have big effects
For each giant planet pair, we consider 80 different locations of the exo-Earth. At each of these locations, we find the stability and habitability probabilities. Then we can integrate over the exo-Earth locations to find a relative habitability for the giant planet pair.
In general, as the exo-Earth's eccentricity increases, it gets more sunlight from its star, making it less habitable in the inner regions and more habitable in the outer regions.
My latest (and likely last!) paper is up on arXiv today! As the title says, it's about the "Relative Habitability of Exoplanet Systems with Two Giant Planets".
Go check it out ➡️ https://arxiv.org/abs/2205.02777
Or for a TL;DR, continue ⬇️
The basic idea is, given an exoplanet system with 2 giant planets, what can we say—from a dynamical perspective—about its ability to host a habitable Earth-like planet?
We focus here on whether the system would be stable and how the exo-Earth's eccentricity would be changed.
Unstable systems (planets ejecting or colliding): not habitable. Easy enough, except the question of whether an arbitrary 3-planet system is stable is, um, HARD. In this case, I used a bunch of different predictive techniques that have been developed by other scientists.
The question of whether an Earth-like planet is habitable and a given semi-major axis and eccentricity is likewise HARD. I (intentionally) use a very simple model here based on existing work in the field. This framework is very adaptable with other habitability models!
I have not been able to bring myself to quit the bird app, and it feels like cheating to just post everything here and there, so I'm at a bit of a loss how to proceed here. In any case, I finally finished my summary video of the recent 2023-2032 Planetary Science & Astrobiology Decadal Survey! There's a lot to get into, so take a look! https://youtu.be/XxKQBbR6LrQ
Dr Erin M. May is an astrophysicist who posts about stars, alien planets, physics, crafts and cats. You can follow at:
You can see May's website at https://erinmmay.github.io
On Thursdays I do the space/astronomy news -- this week featuring:
○ Hubble's 32nd anniversary!
○ JWST is allllmost entirely cooled (4 primary mirror segments to go!)
○ all DNA/RNA building blocks have now been found in meteorites
○ good-bye Axiom-1, hello Crew-4!
○ β Pic exocomets are similar to ours
○ Ingenuity investigates landing debris
I love space!
Come explore our galaxy with me!
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