My Research

My research interests include computational astrophysics, orbital dynamics, and planetary defense. I am currently working with Professor Derek Richardson on studying the dynamics of the binary asteroid 65803 Didymos, the target of NASA's Double Asteroid Redirection Test (DART) mission. DART is a planetary defense mission that will test a kinetic impactor's ability to change the orbit of an asteroid by crashing into Didymos' moon at velocity of ~6km/s. I use pkdgrav, a parallel N-body tree code, to study the dynamical state of the Didymos system. pkdgrav treats each body as an aggregate of spheres to represent a 'rubble-pile', and can calculate collision and contact forces between the particles which allows us to do all kinds of fun stuff. Here is a movie from one of my simulations.

About Me

I grew up in Idaho where I learned to love the outdoors. I don't get to spend much time in the mountains anymore but I go fly-fishing in the DMV area when I get the chance. I moved to California where I majored in physics and astrophysics at UC Berkeley. Go Bears!! I love history and biographies, so I am in the process of reading a biography of every US president. I also love cooking and baking, especially with cast iron. I get roughly half of my calories through sourdough bread, which I make myself. I am a decent golfer, mediocre poker player, and bad chess player but I enjoy all three games equally. Because of my interest in scientific computing, I am (slowly) developing an N-body code for fun called HURRICANE which stands for Harrison Ramsey and JUlian wRote this In C and Made No Errors. The code is perfect, obviously.

Steelhead Fishing, South Fork, Clearwater River, Idaho

Go Bears!

Cal-Stanford football game with Steph.

Kobe Beef #1 with Nate

College graduate with my dad.

A baby sturgeon on the Columbia River.


hagrusa at

Department of Astronomy
Physical Science Complex (PSC), Room 1238
4296 Stadium Dr.
University of Maryland
College Park, MD 20740

Click here to download my CV.