Current Members

Susanna L. Widicus Weaver


Susanna grew up in Mt. Vernon, Illinois. She received a B.S. in Chemistry from Illinois Wesleyan University in 2000. She received a Ph.D. from California Institute of Technology working with Professor Geoff Blake. From 2005 to 2008 she was a postdoc at the University of Illinois at Urbana-Champaign working with Professor Ben McCall. She then moved to Atlanta, GA and became a professor in the Department of Chemistry at Emory University. In 2020, Susanna became a Vozza Professor of Chemistry & Astronomy at the University of Wisconsin-Madison. She now lives in Middleton, WI with her husband, Jeremy Weaver, 5-year old son, Sam, and their cat, Star.

Gustavo Cruz Diaz

Assistant Scientist

Gustavo grew up in Cali, Colombia. He completed his B.S. in Physics at Universidad del Valle. After he was awarded a Ph.D. scholarship, he moved to Spain to study astrophysics at Universidad Autónoma de Madrid. He worked on his Ph.D. dissertation about the effects of ultraviolet irradiation on interstellar ice analogs at the Astrobiology Center (Centro de Astrobiología – CAB, in Spanish), under the supervision of Dr. Guillermo M. Muñoz Caro. Following his graduation, he worked as a postdoctoral fellow at the Sterrewacht (Observatory), Leiden University, in The Netherlands. Then, he joined the Laboratory Astrochemistry team at NASA Ames Research Center, where he worked as a postdoc for 4.5 years. Currently, he is an Assistant Scientist at UW Madison working in the Widicus Weaver Research Group. His research interests are interstellar dust and ices, mass spectrometry, ultraviolet and infrared spectroscopy, and high- and ultra-high-vacuum systems. He likes to camp, bouldering, and good beer.

Chase P. Schultz

6th Year Graduate Student

Current Research: O(1D) Insertion Reactions

Chase received a B.S Summa Cum Laude in Chemistry and Math from Alma College in April of 2018. Most of his undergrad work was spent learning computational chemistry while assisting the development of new theoretical methods. His graduate research has been a large shift, moving to mainly experimental physical chemistry with theory projects on the side. The O(1D) experiment is largely focused on creating terrestrially unstable molecules through the insertion mechanism involved with excited oxygen atoms. Chase has followed the lab from Emory, where he completed his first two years, and is currently in Madison as a first generation UW graduate student for the Widicus Weaver lab.

Will E. Thompson

4th Year Graduate Student

Current research: Experimental modeling of astrophysical ices and observational astronomy

Will received a B.S. in Chemistry from the University of Georgia in 2019. Throughout his undergraduate degree he conducted research in a biophysics lab performing ultrafast spectroscopy experiments on biomolecules and optical materials. After finishing the undergraduate degree, he completed an internship at NASA Goddard Space Flight Center building miniaturized sensors for the detection of prebiotic gases on planetary bodies. Outside of graduate work Will is learning to play the piano, and also enjoys exploring the outdoors and reading.

Photo of Jonathan Rebelsky

Jonathan Rebelsky

4th Year Graduate Student

Current research: Ion/Radical Project

Jonathan received a B.A. in Music and Chemistry from Grinnell College in 2020. Jonathan’s undergraduate research focused on analyzing four-metal perovskitic thin-films for electrocatalytic potential. Outside of graduate work, Jonathan enjoys cooking and music.

Colton Moore


4th Year Graduate Student

Current research: O(1D) Insertion Reactions

Colton received a B.S. Magna Cum Laude in chemistry with a minor in physics from Kansas State University in May 2020. As an undergraduate, he performed research on diffusion behavior in organic nanotubes using imaging fluorescence correlation spectroscopy. He also did science outreach as a member of Alpha Chi Sigma, the professional chemistry fraternity, in his free time. Outside of graduate work, Colton enjoys cooking and spending time with his dogs.

Haocheng Liang

3rd Year Graduate Student

Current research:  Millimeter/submillimeter spectra of prebiotic radicals

Haocheng received a B.S. Cum Laude in chemistry from California State Polytechnic University, Pomona in 2021. Haocheng’s undergraduate research focused on developing a smartphone-based colorimetric method for detecting environmental water pH. Outside of graduate work, Haocheng enjoys playing and watching a variety of sports, playing video games, and photographing.

Collette Sarver

3rd Year Graduate Student

Current research: Experimental modeling of astrophysical ices and observational astronomy

Collette received a B.S. Summa Cum Laude in chemistry with a concentration in physical chemistry and minor in astrophysics from Michigan Technological University in May 2021. As an undergraduate, she performed computational research on the infrared spectra of polycyclic aromatic hydrocarbons (PAHs) found in circumsolar environments in an effort to update the NASA Ames PAH IR Spectral Database (Michigan Space Grant Consortium Fellowship). Outside of research she enjoys hiking, downhill mountain biking, and videogames.

Catherine E. Walker

3rd Year Graduate Student

Current research: Experimental modeling of astrophysical ices and observational astronomy

Catherine received a B.A. in Chemistry with honors and a Certificate in Sustainability and Energy from Northwestern University in 2021. As an undergraduate she conducted research with Prof. Franz M. Geiger on the induction of electric current in metal nanolayers subjected to the motion of ionic fluids. Outside the lab they enjoy music and role-playing games.

Riana Smith

2nd Year Graduate Student

Current research: O(1D) Insertion Reactions and observational astronomy

Riana graduated Cum Laude with a Bachelor of Science in Chemistry with dual astronomy and physics minors at Westminster College in 2022. Riana had participated in many research opportunities in her undergraduate career. The most significant include a study on RR Lyrae-type variable stars working with the Las Cumbres Observatory and the Center for Astronomy and Physics Education Research (CAPER) to monitor the change in intensity fluctuations. Riana also participated in an astrophysics NSF REU in which she worked with the Widicus Weaver group and aided in the astronomical data analysis of the search for pyruvic acid in the interstellar medium. Outside of graduate school, Riana enjoys creatively expressing herself through art, listening to podcasts, and playing video games.

Alejandra Holguin

1st Year Graduate Student

Current research: Observational astronomy and rotational spectroscopy of terrestrially stable molecule

Alejandra grew up in Durango, Mexico. She received her degree in Chemical Engineering at Instituto Tecnologico de Durango in August 2018. Most of her undergrad thesis work focused on developing mirrors for telescopes compatible with active and adaptive optics by means of replication methods based on carbon fiber and epoxy resin. Subsequently, she moved to Mexico City to pursue a master’s degree in Astrophysics at Universidad Nacional Autonoma de Mexico (UNAM). Her work focused on studying the thermal histories of chondrules, which is highly relevant to the evolution of the protoplanetary disk and the formation of planets within it. She graduated with honors in August 2022. Currently, she is studying for her Ph.D. at UW-Madison, working in the Widicus Weaver Research Group. Outside graduate work, she loves writing, reading, traveling, exercising, playing basketball, and doing science outreach.


Ruby W. Neisser

1st Year Graduate Student

Current research:

Ruby graduated summa cum laude from William & Mary with a B.S. in Chemistry. As an undergraduate, she worked in the Kidwell lab and used laser-spectroscopy techniques to investigate the structure and photochemistry of atmospherically relevant molecules. She completed an honors thesis investigating the spectra of Nitrogen-heterocyclic molecules present in brown carbon chromophores. Ruby is now a first-year graduate in the Widicus Weaver group. Outside of the lab she enjoys reading, sewing, and knitting.

Alex Sandquist

1st Year Graduate Student

Current research:

Alex grew up in Mankato, Minnesota. He received his B.S. in chemistry with minors in physics and mathematics from the University of Nebraska-Lincoln in May 2023. As an undergraduate, he performed research in surface modification and functionalization of synthetic vascular grafts with anticoagulants for improved antithrombotic properties. Outside of research, Alex enjoys playing the guitar, video games, hiking and backpacking, and collegiate athletics.

Morgan M. Giese

Research Intern

Current research: Observational astronomy

Morgan received a B.S. in Astronomy-Physics and Mathematics from the University of Wisconsin-Madison in 2022. During undergrad, his research focused on observational work with interferometric observations. Morgan will continue working with the group as a Research Intern while applying to graduate schools. Outside of work, he enjoys playing soccer and spending time with friends.

Carter Brown

Undergraduate Researcher

Current research: O(1D) Insertion Reactions and observational astronomy

Carter is a 4th-year undergraduate student pursuing a Bachelor of Science in Astronomy-Physics and Environmental Studies and a certificate in Data Science. Carter works with the group as an Undergraduate Researcher focusing on observational astronomy and lab experiments. Outside of the lab, she enjoys spending time outdoors and with friends.


Annika Goldstein

Undergraduate Researcher

Current research: Millimeter/submillimeter spectra of prebiotic radicals

Annika is a 2nd-year undergraduate student pursuing a Bachelor of Science in Chemistry. Annika works in the lab as an Undergraduate Researcher focusing on millimeter/submillimeter spectra of prebiotic radicals. Outside of the lab, she enjoys cheering for Boston sports teams and trying new restaurants around Madison.