Our new paper in @Nature re-interprets a key event in Solar System history: the giant planet instability

“Early Solar System instability triggered by dispersal of the gaseous disk”
by @beibeiliu, @sethajacobson and myself.

A thread...

nature.com/articles/s4158…

1/ In a previous thread I explained why we think the Solar System’s giant planets went unstable in their past (the “Nice model”).

Missing pieces of the puzzle: the instability trigger and timing.

https://twitter.com/sraymond_astro/status/1518975174091157504?s=20&t=70VlN9HUtpzILHzzZv5oKQ

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The Solar System wasn’t always this way.

A huge breakthrough in planetary science came from understanding that the giant planets were probably not born on their present-day orbits.

Let’s explore the evolution of the evolution of the outer Solar System…

1/ The Kuiper belt is a collection of small bodies beyond the giant planets’ orbits. It only contains about a tenth of an Earth-mass all told.

But the belt wasn’t always so puny – evidence suggest that many Earth masses of leftover planetesimals used to exist out there.

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Our new paper (led by @izidoro_astro) -- “Planetesimal rings as the cause of the Solar System’s planetary architecture” – just came out in @NatureAstronomy !

Our model proposes that the Solar System formed from 3 rings of planetesimals

A thread

nature.com/articles/s4155…

1/ We are used to thinking that our system formed from a disk. Why rings instead?

Squint at the Solar System from a distance. Almost all of the mass in located 1) between Earth and Venus (rocky stuff), and 2) among the giant planets, which started off a lot closer together.

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Our new paper was just published in @NatureAstronomy (@nmiretroig, Bouy et al)!

Punchline: we found ~100 free-floating planets in a single star-forming region! This roughly doubles the entire sample of known rogue planets.

A thread

nature.com/articles/s4155…

1/ @nmiretroig and Herve Bouy compiled the census of Upper Scorpius: all the stars, brown dwarfs and rogue planets (>4 Jupiter masses)

They analyzed >80,000 images of Upper Sco from the past 20 years (>100 TB) the Cosmic-DANCE project

project-dance.com

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New paper in Nature Astronomy: “An upper limit on late accretion and water delivery in the Trappist-1 exoplanet system”

A thread to explain why this is new and interesting...

nature.com/articles/s4155…

1/ Impacts on planets after they form can:
-Deliver volatiles
-Erode/modify atmospheres
-Cause extinctions
-Make ridiculous movie plots (Deep Impact is my personal favorite asteroid-about-to-kill-everyone movie)

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