Fall
Rishi Chandra is the recipient of a University Fellows Award, a prestigious fellowship offered only to the University of Arizona's highest-ranked incoming graduate students. The award provides an annual stipend, tuition scholarship, and health coverage, in addition to professional development and networking opportunities.
Rishi graduated from the University of Illinois at Urbana-Champaign with a B.S. in physics and planetary science. His primary research interests lie in the analysis of solar system materials, including meteorites and returned samples from asteroids and the moon. He also plans to develop cheaply accessible smartphone virtual reality field trips to exotic geologic locales, such as the Antarctic dry valleys and the lunar surface, to inspire the next generation of geoscientists and to engage the public as the scientific community explores these distant frontiers. Aside from his academic interests, Rishi enjoys virtual motorsports, flight simulation, running, and science fiction literature.
by Rishi Chandra
The University Fellows Award goes to grad students from departments all over campus, and this year's cohort is a tight-knit group. We spent a night at Biosphere 2 for orientation and team-building, which was an unbelievable welcome to Arizona for me in my second week of classes. Through the semester, we have weekly seminars where experts speak with us about practical skills for grad students in any discipline: project management, human-centered design, mentorship and mentee-ship, and more. It's allowed me to connect with students in the humanities, arts, social sciences, and engineering, letting me to explore and present on topics I didn't expect myself to be curious about, such as human-ecosystem coevolution in the Sonoran Desert. It's also given me the opportunity to explore my own interests in new interdisciplinary ways, such as examining ways in which non-Western worldviews can inform Western scientists preparing for human exploration beyond low Earth orbit. Connecting with scholars from other disciplines has offered me new perspectives on familiar problems, so I'm excited to see where the connections I've made with my peers in the UF program lead me in the coming years.
Catalina Sky Survey Tops off 2021 with a Rare Bright Comet Discovery
Gregory Leonard discovered the comet using the Catalina Sky Survey's 1.5-meter (60-inch) telescope on Mount Lemmon. Photo by Camillo Scherer.
Every night with clear skies, astronomers with LPL's Catalina Sky Survey (CSS) scan the sky for near-Earth asteroids – space rocks with the potential of venturing close to Earth at some point. During one such routine observation run on Jan. 3, CSS observer Gregory Leonard spotted a fuzzy patch of light tracking across the starfield background in a sequence of four images taken with the 1.5-meter reflector telescope at the summit of Mount Lemmon, Arizona. The dot's fuzzy appearance, combined with the fact that it had a tail, was a dead giveaway that he was looking at a comet. This was the first comet discovered in 2021, and it was thus designated C/2021 A1 (Leonard).
At the time of discovery, the comet was 400,000 times dimmer than what the human eye can see and was detected as a fuzzy patch of pixels tracking across the background stars in four telescope images. In the past, comets were discovered visually by very dedicated astronomers who spent countless hours scanning the night skies with a telescope. In recent decades, most comets are discovered incidentally by surveys tasked with finding near-Earth asteroids like the NASA-funded Catalina Sky Survey (CSS), Pan-STARRS, ATLAS and NEOWISE projects.
Most long-period comets such as Comet Leonard hail from the Oort Cloud, a vast region surrounding our solar system at distances no spacecraft has ever come close to, not even the two Voyager probes, which have officially left the solar system and entered interstellar space. Out there, suspended in the vast interstellar void where temperatures are close to absolute zero, are billions of orbiting comets balanced in a delicate tug-of-war of extremely weak gravitational forces between the distant sun and the rest of the Milky Way. Slight perturbations of this precarious balance of forces may nudge a chunk of ice and dust out of the Oort Cloud and send it onto a trajectory toward the Sun.
Comets are small bodies of the Solar System which are largely comprised of different types of ices and dust. Most comets have undergone very little processing since the beginning of the Solar System since they spend most of their lifetime at large heliocentric distances in the most frigid regions of space. Cometary nuclei therefore contain pristine samples of grains and gas from the protosolar nebula in which they formed; thus studying comets allows us to peek into the early conditions of our Solar System’s formation.
The most abundant ice and contributor to cometary activity through sublimation is water-ice, but C/2021 A1 (Leonard) was observed to be active beyond the water-ice sublimation zone. This means that other mechanisms different from water-ice sublimation were responsible for the activity, possibly through the sublimation of other icy compounds such as carbon monoxide, carbon dioxide, or different exothermic mechanisms.
Comet Leonard made its closest approach to Earth on Dec. 12, at which point it was still more than 21 million miles away. "This is the last time we are going to see the comet," Leonard says. "It's speeding along at escape velocity, 44 miles per second. After its slingshot around the Sun, it will be ejected from our solar system, and it may stumble into another star system millions of years from now."
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Dr. Daniella DellaGiustina will join LPL as an Assistant Professor this January (2022).
Dani is Deputy Principal Investigator for the OSIRIS-REx mission, responsible for oversight of extended mission activities. Previous to being named Deputy PI, Dani served as the mission’s Image Processing Lead Scientist. Dani is an alumna of the University of Arizona, where she earned a B.S. in Physics and Ph.D. in Geosciences. She also holds an M.S. in Computational Physics from the University of Alaska. As an undergraduate at UArizona, Dani minored in planetary sciences at LPL and was an Arizona NASA Space Grant intern. Her Space Grant project on characterizing mineral phases in meteorites was supervised by Dante Lauretta, now Principal Investigator for OSIRIS-REx. Dani continued to work at LPL with Dante Lauretta and Michael Drake, leading a student experiment on the Phase A Discovery OSIRIS Mission until the end of her undergraduate career. In graduate school, she fused remotely-sensed observations of Earth’s cryosphere with the numerical modeling techniques to understand the dynamics of the Greenland ice sheet. Her Ph.D. dissertation was on the subject of Signal Processing of Seismic and Image Data for Planetary Exploration. In her spare time, Dani is an avid rock-climber and outdoor enthusiast.
In this Sci&Tell interview, Regents Professor and OSIRIS-REx Principal Investigator Dante Lauretta discusses the patience required when working in science and how his passion for science stems from his love for exploring.
A study led by Professor Erik Asphaug suggests that the protoplanet most likely hit Earth twice. The first time, the impactor (dubbed "Theia") only glanced off Earth. Then, some hundreds of thousands of years later, it came back to deliver the final blow.
In this image, the proposed hit-and-run collision is simulated in 3D, shown about an hour after impact. Theia, the impactor, barely escapes the collision. A. Emsenhuber / University of Bern / University of Munich
Professor Amy Mainzer is Principal Investigator for NEOWISE and for NEO Surveyor, two space missions designed to survey the Solar System for potentially hazardous objects—so it's no wonder that she was selected to be the science advisor for the Netflix film, Don't Look Up. In this Wired interview, Professor Mainzer breaks down a few scenes from film and explores the science behind near-Earth objects. Read more about Professor Mainzer's work on the film in the article from Universe Today.
By Nick Prevenas, University Communications
Oct. 27, 2021
The University of Arizona has once again been recognized as one of the world's top 100 research institutions by U.S. News & World Report.
UArizona ranked No. 99 out of 1,750 higher education institutions across 90 countries in the 2022 Best Global Universities ranking. The university was No. 42 among universities in the U.S. and No. 22 among public universities.
"It is gratifying to see the University of Arizona listed alongside many of the world's premier academic research institutions," said University of Arizona President Robert C. Robbins. "Our university is home to many breathtaking scientific innovations, and it is upon this foundation that our faculty members seek to make further extraordinary discoveries."
U.S. News & World Report's Best Global Universities ranks colleges and universities in 43 separate subjects – up from 38 the year before. The University of Arizona earned a spot on 32 of the subject rankings lists.
UArizona earned its top placement in the space science category, placing No. 10 overall, No. 7 in the U.S. and No. 2 among public universities – all up one spot from last year's rankings. The university earned top marks for its research reputation in space sciences, along with the number of citations and publications by UArizona researchers.
The university's overall research reputation ranked No. 46 in the U.S. and No. 93 globally.
"The resolve and innovative spirit of researchers across campus are at the heart of the university's outstanding research reputation," said Elizabeth "Betsy" Cantwell, senior vice president for research and innovation. "From our commitment to building resilience amid a swiftly changing climate, to our leadership of NASA's groundbreaking OSIRIS-REx mission returning an asteroid sample to Earth, to our pioneering work understanding individualized health needs through the NIH-funded All of Us Program, University of Arizona research creates real-world solutions in nearly every scientific discipline."
UArizona earned top-100 global placements for its programs in geosciences (No. 26), arts and humanities (tied for No. 42), environment/ecology (No. 42), plant/animal sciences (No. 53) and biotechnology and applied microbiology (No. 86).
The eighth annual Best Global Universities rankings are produced to provide insight into how research institutions compare throughout the world. The rankings focus specifically on schools' academic research and reputation overall. To produce the global rankings, which are based on data and metrics provided by analytics company Clarivate, U.S. News & World Report uses a methodology that focuses on 13 indicators to measure research performance.