REU Stories


It’s amazing how much you can learn in ten weeks. MATLAB went from being this weird uncomfortable program to one I’m proficient in. I now know about the history of the Arecibo Telescope, from sinkhole to world-class telescope, with line feeds and super-complicated optics. I almost understand galactic HI observations. I had never heard of LIDAR before, and now I can explain what it does. (Looks at the ionosphere from 80-100 km with pretty lasers.) My Spanish proficiency doubled, as did my knowledge of statistics. I’ve become more comfortable using command lines and troubleshooting code. I learned about the Saturn system and the Cassini mission. I’m now much better at explaining and presenting my research.

I should back up for context. I’m Clarissa, an Astronomy major at Mount Holyoke College, and I spent this summer in the REU program at the Arecibo Observatory, working with Dr. Edgard Rivera-Valentín, aka Ed. To be honest, I ended up running laps around Arecibo’s dish every morning not because I dreamed about the .59 mile circumference dish, but because Arecibo was one of the few internships with planetary science. I now dream of the dish, sometimes about falling onto it from the telescope platform. I didn’t know what I had signed up for; before this summer I had never been to Puerto Rico, had no idea what I would be researching, and knew no one else in the program.

The REU program at Arecibo was amazing. Like I said earlier, I learned so much in such a short time. Working with Ed, I studied the cratering history of Rhea and Dione, looking to constrain the how much “stuff” was flying around during the early stages of our Solar System. To do this, I learned a lot about Solar System formation models and about Saturn’s moons Rhea and Dione. By comparing computer simulations to the observed cratering record on icy moons, we can constrain how much material was in the so-called planetesimal disk. I ran IDL codes to model impacts on the bodies, running through 16 possible disk scenarios. In understanding this code, I was introduced to Monte Carlo statistics, error propagation, and the computer language IDL. The code asked the computer to keep track of how many impacts occurred at any location on the body, the melt production of the impacts, the velocity and total impact mass of objects striking the surface. We then ran a statistical analysis of the simulations, and compared it to the crater counts of Rhea and Dione, collected previously by Michelle Kirchoff.  I then took Ed’s MATLAB code and edited it for Rhea and Dione, and built a new complementary code to incorporate error and analyze the generated data to find how much material in the Solar System was required to best match the observed cratering record on the bodies. It was a lot of troubleshooting code, error messages, and being confused, which ultimately paid off.

Through the REU colloquia talks I learned about the history of Arecibo, galactic HI, the ionosphere, LIDAR, what makes a galaxy a galaxy, the optics of the telescope, and so much more. The staff scientists at Arecibo were all super into their research and more than happy to have the students hanging around and asking questions.

Team Radar, the people responsible for zapping asteroids with radar to study their position and speed in order to defend the world against possible impacts, welcomed the REU students to all of their stressed-out observation nights. I enjoyed going to tea time and listening to the people gossip about their lives and the observatory.

In the weekends we, the REU students, bonded and took trips around the island. We took a Tanama river tour, went to the Puerto Rican Arts festival, and visited Old San Juan. Robert Minchin, one of the REU mentors and an astronomer at the observatory, took us to see the Puerto Rican Parrots in a near-by reserve. (We heard them, but sadly did not see them.) Lucy Lopez, the HR director at the Observatory, had us over to her house in Cabo Rojo for the fourth of July, which was a part of the island I never would have thought to go to. It was really cool to see the dry forest and the salt flats, and I found a coral fossil in Playa Sucia Beach!

My internship at Arecibo Observatory was amazing, and I’m super grateful for the research experience and friends I gained this summer!



 (This is me. I love Coco Frio and am very upset that I can’t find it in Texas.)



(We got to poke buttons for the telescope! At 4am!)