@harrisonagrusa.bsky.social
Asteroid 28888 Postdoc at Observatoire de la Côte d’Azur
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 :)
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…
25.06.2025 17:29 — 👍 1 🔁 0 💬 0 📌 0If you don't read the paper, at least enjoy this movie of our Figure 2! In this simulation, q is the particle's pericenter, normalized to the primary's long axis. The point is that you need q>1 to avoid reimpacting the primary during pericenter passage, and that is not always easy!
07.05.2025 16:20 — 👍 3 🔁 0 💬 1 📌 0
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
01.05.2025 20:18 — 👍 1 🔁 0 💬 0 📌 0
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").
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
A cherry tree in full bloom with a rocket in the background.
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!
04.04.2025 04:54 — 👍 2 🔁 0 💬 0 📌 0
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!
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!
I just compute the orbital elements, then calculate the corresponding xyz positions over 360 degrees of true anomaly. Then it’s a simple ax.plot(x,y,z). I wanted to have the lines fade away like in Rebound but it was a bit more work.
21.03.2025 18:48 — 👍 2 🔁 0 💬 1 📌 0Playing around with some renderings of DART impact ejecta simulations. It’s amazing what you can do with @matplotlib.org and @reboundbot.bsky.social !
21.03.2025 17:00 — 👍 41 🔁 7 💬 1 📌 2
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...
27.02.2025 21:49 — 👍 1 🔁 0 💬 0 📌 0Just wait until the garden is up and running. You’re gonna hate me
27.12.2024 20:13 — 👍 3 🔁 0 💬 0 📌 0
Wooden dining table and five chairs
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!
27.12.2024 15:34 — 👍 5 🔁 0 💬 1 📌 0Ralphie is my style icon
25.12.2024 20:39 — 👍 1 🔁 0 💬 0 📌 0This image should be properly credited. It was made by Yun Zhang for her paper on 'Oumuamua: arxiv.org/abs/2004.07218
13.12.2024 21:07 — 👍 0 🔁 0 💬 0 📌 0I saw and would totally apply but this I think New Zealand is outside the allowable parameter space of my two-body problem :)
05.12.2024 20:26 — 👍 1 🔁 0 💬 0 📌 0I also installed mods to include Jupiter Trojans and KBOs, so maybe New Horizons or Lucy are next on the list. Or maybe I get back to work...
05.12.2024 19:34 — 👍 2 🔁 0 💬 0 📌 0I launched in 1978 (a year late) so I ended up having to skip Saturn. But my flybys of Jupiter, Uranus, and Neptune needed less than ~50 m/s of mid-course corrections. Maybe I am a real rocket scientist?? I forgot how great this game is!
05.12.2024 19:34 — 👍 2 🔁 0 💬 1 📌 0
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 :)
05.12.2024 19:34 — 👍 1 🔁 0 💬 2 📌 0
Another one. This paper is “The feasibility of deflecting asteroid 2017 PDC using neutral beam propulsion” by DeCicco et al., 2019 (Don’t worry, 2017 PDC is not a real asteroid!)
22.01.2024 21:51 — 👍 3 🔁 0 💬 0 📌 0In fact there was a line in the show where they mentioned all of the DART results were published openly!
22.01.2024 20:43 — 👍 4 🔁 0 💬 1 📌 0
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.
22.01.2024 18:52 — 👍 29 🔁 3 💬 4 📌 1Thanks!! That is if I ever end up posting anything :)
28.12.2023 11:06 — 👍 1 🔁 0 💬 0 📌 0
