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Harrison Agrusa

@harrisonagrusa.bsky.social
56 followers 93 following 25 posts

Asteroid 28888 Postdoc at Observatoire de la Côte d’Azur

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Harrison Agrusa @harrisonagrusa.bsky.social · 25/08/2026
A very nice paper by @raducan.bsky.social. I had a fun time playing a small part!
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Michael Busch @michael-w-busch.bsky.social · 07/07/2026
For #ACM2026, @harrisonagrusa.bsky.social suggests up to 30% contact binaries in the asteroids resulting from large collisions. Radar samples of near-Earth asteroids have counted fewer than that - but not all of the contact binaries would be recognized.
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Harrison Agrusa @harrisonagrusa.bsky.social · 06/07/2026
I’ve been exploring gravitational reaccumulation after asteroid catastrophic disruptions and am finding contact binaries are super common outcomes! I can’t help but notice how similar Torifune looks compared to this fragment from one of my simulations, which I will present tomorrow at #ACM2026
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Harrison Agrusa @harrisonagrusa.bsky.social · 27/04/2026
I've been working on a new N-body code and wanted a fun way to demonstrate that the contact physics is correct (at least qualitatively). So here is a self-gravitating Newton's cradle!
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Sabina Raducan @raducan.bsky.social · 12/12/2025
New paper out 🥳 Using data from #NASA #Lucy mission and a series of numerical simulations, we show that #Selam, the moon of #Dinkinesh, likely formed through a series of at least four low-velocity collisions between similarly sized moonlets. www.nature.com/articles/s41...
nature.com
Multiple moonlet mergers as the origin of the Dinkinesh-Selam system - Nature Communications
Space missions imaging small asteroid moons revealed the variety in shapes. Here, the authors show that repeated low-speed collisions can explain the shape of Selam, which is the smaller component in ...
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Harrison Agrusa @harrisonagrusa.bsky.social · 25/06/2025
Current status: gardening with a view. Had to harvest ~1/4 of my onions early because somebody has a habit of trampling on them in search of the ball…
A garden with a couple raised beds with tomatoes, cucumbers, lettuces, courgettes, and aubergine. A dog is in one corner with a view of the Mediterranean in the other. Onions of various sizes. Mostly small because the dog trampled their stalks :)
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Harrison Agrusa @harrisonagrusa.bsky.social · 07/05/2025
Had a fun time being a part of this paper where we used a combination of SPH and N-body simulations to explore how asteroid satellites form from collisions. arxiv.org/abs/2505.03325
arxiv.org
Satellite formation around the largest asteroids
Satellites around large asteroids are preferentially found among those with the most rapid rotation and elongated shape. The taxonomic statistics are similarly skewed; in total, 13 asteroids larger th...
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Dr. Raphael Marschall @spacemarschall.net · 20/04/2025
2 hours and 4 minutes to the closest approach of Lucy with #asteroid (52246) Donaldjohanson [DJ]. ↔️ current distance to DJ: 100 thousand km ☀️ current phase angle: 13.98° 🪨 estimated size of DJ on L'LORRI camera: 6-10 pixels ▶️ www.whereIsLucy.space #PlanetSci #SciComm
The image presents a dark background dominated by a series of concentric circles representing distances in thousands of kilometers (km). These circles are subtly colored in shades of teal/blue. A bright white line cuts across these circles diagonally, representing the path or trajectory of the Lucy spacecraft. A small green dot marks the "point of closest approach" of the Lucy with asteroid Donaldjohanson. At the top right, a light gray line shows the trajectory of asteroid Donaldjohanson (DJ). 

At the top left, text indicates the "Encounter Mode" with a small red dot possibly showing "live updates." Further text displays the name of the asteroid (Donaldjohanson), data about the encounter, including the date and time, the distance, and the phase angle.

A rectangular box in the lower right contains additional information about the observation, specifically the field of view of the L'LORRI instrument and the apparent size of the object in pixels. The box also clarifies that the object's shape and exact size are not precisely known, providing an estimated diameter of 3-5 km, citing a source ("Masiero et al. 2011").
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Harrison Agrusa @harrisonagrusa.bsky.social · 04/04/2025
In Japan for the next 10 days for a few exciting meetings. Today and tomorrow, I am at JAXA’s ISAS for a Hayabusa2# science team meeting. What a great excuse to visit when the cherry blossoms are in full bloom!
A cherry tree in full bloom with a rocket in the background.
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Dr. Nick Attree @nickattree.eurosky.social · 24/03/2025
Working up here at the Obervatoire de la Côte d'Azur, #Nice today and gave a talk on #Comet activity modelling this morning #PlanetSci. Thanks to everyone who came and thanks very much to @harrisonagrusa.bsky.social for hosting me!
Grand railing-ed walkway of an old building with a cloudy view of a city and bay behind.Chalkboard and TV minister displaying a picture of a comet plus the talk title slides. outside the window and old building is visible. Rooftop view of a city sprawling sway to the sea. Clouds still cover part but sun is beginning to peak through. View of restaurant tables before a wide window with sweeping views of the city and blue sea, now in the sun!
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Harrison Agrusa @harrisonagrusa.bsky.social · 21/03/2025
Playing around with some renderings of DART impact ejecta simulations. It’s amazing what you can do with @matplotlib.org and @reboundbot.bsky.social !
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Harrison Agrusa @harrisonagrusa.bsky.social · 27/02/2025
Happy to announce that I’ve been selected as a participating scientist on NASA’s Lucy mission. I can’t wait to join the team and explore the Trojans! science.nasa.gov/uncategorize...
science.nasa.gov
NASA Selects Participating Scientists to Join Lucy Asteroid Mission - NASA Science
NASA has selected eight participating scientists to join its Lucy mission to the Jupiter Trojan asteroids. These asteroids are remnants of our early
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Harrison Agrusa @harrisonagrusa.bsky.social · 27/12/2024
New (to me) handmade table and chairs found at a flea market in Nice. Restoring it now with some beeswax. €100 and will probably outlive me. This room is finally coming together!
Wooden dining table and five chairs
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Harrison Agrusa @harrisonagrusa.bsky.social · 05/12/2024
I decided it would be a good idea to procrastinate on job applications and play some Kerbal Space Program instead. Using a mod to play with a 1/9 scale real solar system, did a nice Voyager style mission. Here are my Jupiter and Neptune/Triton flybys :)
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Harrison Agrusa @harrisonagrusa.bsky.social · 22/01/2024
I found a fun Easter egg in For All Mankind. They used real DART papers as props for a scene related to altering the orbit of an asteroid! On the left is Rivkin et al. 2021 and on the right is Hirabayashi et al. 2022.
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