Between my normal meetings and writing, I'm watching a few talks at the American Astronomical Society's (AAS) Division for Dynamical Astronomy (DDA) annual meeting this week.
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Oooo he's got a bunch of orbital sonification on his website! https://shadden.github.io/sonification/
Oooo really neat to hear a chord change during an N-body simulation when stability is lost and a planet swaps to a different resonance.
Resonant chain migration behaves like masses on springs, says it's like vibrato! Cool.
"So that's a lot of fun, but so what?" Unstable modes grow or decay depending on how eccentricities are damped.
@sundogplanets Really Cool!
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Konstantin Batygin (Caltech): most common planets are super-Earths on very short orbits. How do they not fall into their star? How do they pick which resonance to lock in to? (Bonus points for joke about a system with a 6:7 resonance for everyone with middle-school-aged kids)
Giant equation in a confetti explosion (this guy likes giving talks). Shows that 6:7 resonance requires planets to form simultaneously at 1-3AU: the "planet factory ring"
@sundogplanets
Do we still have sampling issues? Is “most common planets are super-Earths on very short orbits” because those are easier to detect than super-Earths on longer orbits, or sub-Earths? -
Leia Shen & Kavi Dey (Harvey Mudd College) current categorization looking for asteroid dynamical families takes ~30 minutes of computation per asteroid. Vera Rubin observatory will discover 10 million more asteroids. Using machine learning and computationally cheaper asteroid properties to find families. Code is available, but they only gave it as QR code not a link...sigh.
Wait … Harcourt Fenton Mudd conned his way into owning … a *college*??
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As part of the CV-rejiggering for academic stuff that I previously complained about, I also need to update my academic website (which is embarrassingly simple, but at least I didn't write it in 1999 and it doesn't have a dancing-linux-penguin-gif like Some Other Academics). Will be trying to do that while listening to the next set of #DDA2026 talks
@sundogplanets But surely it needs to be sprinkled with goat emoji! WIth a good boy looking after them
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Paul Wiegert (U. Western Ontario): finding interstellar meteors is really hard! Lots of meteors are from comets with high-eccentricity orbits, hard to get good enough data to measure meteor pre-impact orbits. There *are* interstellar meteors, just not as many as that Harvard astronomer (who the speaker did not name) seems to think, and none have been conclusively discovered yet.
Good on PW for not naming him. That particular astronomer doesn't need any more promotion.
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Paul Wiegert (U. Western Ontario): finding interstellar meteors is really hard! Lots of meteors are from comets with high-eccentricity orbits, hard to get good enough data to measure meteor pre-impact orbits. There *are* interstellar meteors, just not as many as that Harvard astronomer (who the speaker did not name) seems to think, and none have been conclusively discovered yet.
Apostolos Christou (Armaugh Obs.) this talk title is hilarious "Larger asteroids stay sober, smaller asteroids get drunk"
Wow what a cartoon!
Small asteroids end up with gaussian distributions around the family centre.
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Apostolos Christou (Armaugh Obs.) this talk title is hilarious "Larger asteroids stay sober, smaller asteroids get drunk"
Wow what a cartoon!
Small asteroids end up with gaussian distributions around the family centre.
Daniel Durda (SWRI): Overview talk. The asteroid belt is a fossilized collisional system - the size distribution (particularly waves in size dist) tells us about the past. Dust production is "spikey": lots right after a big collision.
Lots of work on Chicxulub impact, where does debris land? (Back into atmosphere, heating it up, burning everything)
Used Ames gun to smash real meteorites and study dust from them.
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Apostolos Christou (Armaugh Obs.) this talk title is hilarious "Larger asteroids stay sober, smaller asteroids get drunk"
Wow what a cartoon!
Small asteroids end up with gaussian distributions around the family centre.
@sundogplanets we need more scientific illustrations like this
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Daniel Durda (SWRI): Overview talk. The asteroid belt is a fossilized collisional system - the size distribution (particularly waves in size dist) tells us about the past. Dust production is "spikey": lots right after a big collision.
Lots of work on Chicxulub impact, where does debris land? (Back into atmosphere, heating it up, burning everything)
Used Ames gun to smash real meteorites and study dust from them.
I should note that this session (and a at least one other) at #DDA2026 are tributes to Stan Dermott, who wrote the Solar System Dynamics bible, and taught a LOT of students.
I guess I have a 1-degree-removed connection here? The postdoc I first worked with, Beth Holmes, who taught me a lot, when I was a baby undergrad, had just finished her PhD with him. (She died from a heart condition while I was still an undergrad)
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Paul Wiegert (U. Western Ontario): finding interstellar meteors is really hard! Lots of meteors are from comets with high-eccentricity orbits, hard to get good enough data to measure meteor pre-impact orbits. There *are* interstellar meteors, just not as many as that Harvard astronomer (who the speaker did not name) seems to think, and none have been conclusively discovered yet.
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I should note that this session (and a at least one other) at #DDA2026 are tributes to Stan Dermott, who wrote the Solar System Dynamics bible, and taught a LOT of students.
I guess I have a 1-degree-removed connection here? The postdoc I first worked with, Beth Holmes, who taught me a lot, when I was a baby undergrad, had just finished her PhD with him. (She died from a heart condition while I was still an undergrad)
Mark Wyatt (U. of Cambridge) talking about dynamical effects of planets on debris disks (I LOVE this stuff). This is true in our own solar system, zodiacal dust is affected by our planets' orbits.
Ooo Fomalhaut, my favourite disk system! The brightness variations in the disk place constraints on the forced eccentricities resulting from unseen planets in the system.
Fom b is a dust cloud, not a planet, which I am incredibly proud I wrote about years ago! Now proven from JWST images!
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Apostolos Christou (Armaugh Obs.) this talk title is hilarious "Larger asteroids stay sober, smaller asteroids get drunk"
Wow what a cartoon!
Small asteroids end up with gaussian distributions around the family centre.
@sundogplanets Makes me think of the Douglas Adams line:
"You won't like it. It's a bit like being drunk."
"What's wrong with being drunk?"
"Ever ask a glass of water?"
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Mark Wyatt (U. of Cambridge) talking about dynamical effects of planets on debris disks (I LOVE this stuff). This is true in our own solar system, zodiacal dust is affected by our planets' orbits.
Ooo Fomalhaut, my favourite disk system! The brightness variations in the disk place constraints on the forced eccentricities resulting from unseen planets in the system.
Fom b is a dust cloud, not a planet, which I am incredibly proud I wrote about years ago! Now proven from JWST images!
J.-C. Liou (NASA Chief Scientist for Orbital Debris!!) Overview of his career work: started with work on zodiacal dust dynamics, with PR drag and resonances. Showed how outer asteroid belt is depleted by Jupiter MMR sweeping. Then dynamics of cometary dust collected from high altitude aircraft, and Kuiper Belt dust structures.
Now works on distribution of human-made debris pieces in orbit. Now at point where collisions dominate debris creation. Active removal required for long-term.
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Mark Wyatt (U. of Cambridge) talking about dynamical effects of planets on debris disks (I LOVE this stuff). This is true in our own solar system, zodiacal dust is affected by our planets' orbits.
Ooo Fomalhaut, my favourite disk system! The brightness variations in the disk place constraints on the forced eccentricities resulting from unseen planets in the system.
Fom b is a dust cloud, not a planet, which I am incredibly proud I wrote about years ago! Now proven from JWST images!
@sundogplanets This is unbelievably dumb, but perhaps you will enjoy this moronic 1997 punk earworm "Fomalhaut" from Kansas band Danger Bob.
https://www.youtube.com/watch?v=9ynTun5ePAo -
J.-C. Liou (NASA Chief Scientist for Orbital Debris!!) Overview of his career work: started with work on zodiacal dust dynamics, with PR drag and resonances. Showed how outer asteroid belt is depleted by Jupiter MMR sweeping. Then dynamics of cometary dust collected from high altitude aircraft, and Kuiper Belt dust structures.
Now works on distribution of human-made debris pieces in orbit. Now at point where collisions dominate debris creation. Active removal required for long-term.
Ashley Espy Kehoe (Embry-Riddle Aeronautical University)
Recurring theme for Stan Dermott memorial talks: plots are IMPORTANT! (totally agree) So here's a beautiful plot she showed from 1986, that shows how dust bands are created in Solar System (orbital caustics!)
Dust bands tell us about asteroid collisional families. Takes millions of years for full band to form, partial bands give timescales since major collisions, COOL. Dust band structure was confirmed by WISE data.
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Ashley Espy Kehoe (Embry-Riddle Aeronautical University)
Recurring theme for Stan Dermott memorial talks: plots are IMPORTANT! (totally agree) So here's a beautiful plot she showed from 1986, that shows how dust bands are created in Solar System (orbital caustics!)
Dust bands tell us about asteroid collisional families. Takes millions of years for full band to form, partial bands give timescales since major collisions, COOL. Dust band structure was confirmed by WISE data.
Great way to end the session with a shout-out to Brian May, who started his PhD, took a decades-long break to be a rock star, then finished his PhD, on zodiacal dust, with some help from Stan Dermott. #DDA2026
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Great way to end the session with a shout-out to Brian May, who started his PhD, took a decades-long break to be a rock star, then finished his PhD, on zodiacal dust, with some help from Stan Dermott. #DDA2026
@sundogplanets Maybe it’s not too late for me then 🥹.
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Great way to end the session with a shout-out to Brian May, who started his PhD, took a decades-long break to be a rock star, then finished his PhD, on zodiacal dust, with some help from Stan Dermott. #DDA2026
@sundogplanets
Rock . . . Star . . . Gazer?
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Great way to end the session with a shout-out to Brian May, who started his PhD, took a decades-long break to be a rock star, then finished his PhD, on zodiacal dust, with some help from Stan Dermott. #DDA2026
@sundogplanets
Guitarist of the stars.
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Great way to end the session with a shout-out to Brian May, who started his PhD, took a decades-long break to be a rock star, then finished his PhD, on zodiacal dust, with some help from Stan Dermott. #DDA2026
Mark Dodici (U. of Toronto): looking at eclipsing compact triple star systems (two stars orbiting each other, with a third orbiting the inner two). Outer orbits are very circular in observed systems, must be circularized by tides, will shrink inner orbit. Uses Reboundx to simulate this, helps to hone in on tidal Q parameter. So far, not getting useful results, all outside observations. Still working on it, need better tidal model.
