The Department of Astronomy and Planetary Science at NAU is home to active faculty research programs in several exciting areas in the lab, at the telescope, and participating in NASA Solar System Exploration missions.
Current research projects:
Astrobiology Accordion Closed
What controls the distribution and activity of life in the coldest and driest locations on Earth? Dr. Salvatore’s work is revolutionizing how we search for life on Earth and other planets. His research team conducts field work in the McMurdo Dry Valleys of Antarctica to study the activity of photosynthetic microbial communities and to compare these observations with orbital measurements. The goal is to be able to model the distribution, activity, health, and biochemical properties of these systems remotely to further understand the conditions required for life to thrive.
Exoplanet Biosignatures and Characterization
Dr. Robinson is actively engaged in developing the next generation of future space telescopes that would be capable of studying Earth-like exoplanets around our nearest stellar neighbors. Here, Dr. Robinson’s group (the HABLab) is working to understand how signs of life (biosignatures) and habitability (i.e., surface oceans) could be inferred from noisy, spatially-unresolved observations. A key aspect of life on modern Earth is that it drives our atmosphere into a state of chemical disequilibrium, and HABLab members want to understand if similar signatures of disequilibrium could be detected for exoplanets.
Dr. Trilling is carrying out several projects in experimental astrobiology in collaboration with faculty in NAU’s Biological Sciences department. In the first, he is measuring to what degree microbial life can survive in increasingly Mars-like conditions through a series of experiments with sealed containers using both local soil from Northern Arizona and Mars analog soils. In the second, his team is carrying out physiology experiments on laboratory mice to determine the short-term and long-term effects of exposure to lunar and asteroidal dust. They are using reverse-transcriptase quantitative PCR and histology and studying airway microbiome composition to identify and quantify pulmonary epithelial inflammation, tissue remodeling, and pulmonary function pathology resulting from exposure to dust simulants. Finally, in the third, Trilling and colleagues are studying remediation techniques for perchlorates, which are present on Mars at lethal concentrations that would prevent food production (farming) there.
Exoplanets & Planetary Formation Accordion Closed
Formation & Evolution of Planetary Systems
Dr. Trilling is using the Hubble Space Telescope to discover very faint Kuiper Belt Objects. The orbits and physical properties of these distant objects will help constrain the origin of the Solar System.
Atmospheres are the lens through which we understand the formation and history of countless planets and brown dwarfs. Dr. Robinson uses planetary atmospheres to characterize the composition and thermal state of astronomical objects. His interest in planetary atmospheres spans exoplanets, Solar System planets, and brown dwarfs.
Laboratory Studies of Planetary Materials Accordion Closed
|Devon Burr||Christopher Edwards||Josh Emery|
|Mark Loeffler||Mark Salvatore||Stephen Tegler|
Dr. Emery measures laboratory spectra of analogs to materials found on asteroid surfaces in order to facilitate interpretation of telescopic observations. The materials include terrestrial minerals as well as meteorites. Investigations generally include petrologic and mineralogic characterization of the samples to ground the spectral data. We typically attempt to simulate different environmental conditions on asteroid surfaces to investigate the effects on measured spectra.
Evolution of Planetary Surfaces
Dr. Loeffler runs the Processes, Environments, and Astrochemistry on Extraterrestrial Surfaces (PEAXS) Laboratory at NAU, which studies the physical, chemical, and structural evolution of planetary surfaces.
Dr. Burr conducts experiments in the high-pressure Titan Wind Tunnel at the NASA Ames Research Center to determine the minimum wind speed needed to form the vast dunes seen on Titan.
Dr. Edwards designs and builds prototype instruments for use in the laboratory, the field, and ultimately space. Specifically, he works with novel thermal infrared techniques designed to maximize scientific output while minimizing size, weight, and power.
Dr. Tegler studies ices relevant to the surfaces of Kuiper Belt Objects in the Astrophysical Ice Laboratory using transmission and Raman spectroscopy.
Dr. Burr conducts experimental studies into the effects on icy cobbles of transport in liquid nitrogen rivers on Titan. They do this research using the Titan Tumbler, developed by Dr. Joe Levy at Colgate University, to tumble icy cubes at liquid nitrogen temperatures to quantify the amount of rounding, size reduction, and resulting fine sediment production.
Dr. Salvatore and Dr. Edwards collaborate in the laboratory analysis of terrestrial samples for comparison to remotely acquired signatures on planetary surfaces.
Observational Planetary Science Accordion Closed
|Josh Emery||Stephen Tegler||Cristina Thomas|
|David Trilling||Chad Trujillo|
Characterization of Kuiper Belt Objects
Drs. Emery, Tegler, Trilling, and Trujillo are all involved with the identification and characterization of Kuiper Belt Objects using a multitude of instruments and techniques. For example, Dr. Trujillo is actively searching the outer reaches of our Solar System to find extremely distant Trans-Neptunian minor planets and dwarf planets — the unusual orbits of these objects suggest that there may be an undiscovered giant planet lurking in our outer Solar System. Dr. Emery led a large survey of Centaurs and KBOs with the Spitzer space telescope to investigate ices and organics on their surfaces, and he looks forward to continuing those investigations with the James Webb Space Telescope.
Composition of Asteroids
Dr. Thomas uses visible and near-infrared spectroscopy to characterize the composition of asteroids. She recently completed a ground-based spectral survey of the Massalia, Merxia, and Agnia families of asteroids using the NASA Infrared Telescope Facility (IRTF) and SOAR telescopes.
Dr. Emery investigates compositions of Main Belt and Trojan asteroids with reflectance spectroscopy at visible and near-infrared wavelengths and emission spectroscopy at mid-infrared wavelengths using ground- and space-based telescopes. He has particularly focused on the 2–4 μm region to study asteroidal volatiles and organics.
Icy Moons / Ocean Worlds
Dr. Emery studies the surface compositions of the moons of the giant planets to understand the compositions of ices and structures of the near surface layer.
Investigation of Near-Earth Asteroids
Dr. Trilling uses telescopes all over the world and in space to study the physical properties of Near-Earth Asteroids. He leads two projects to develop and enhance instrumentation to support this research. Dr. Thomas is a co-investigator on the Mission Accessible Near-Earth Object Survey (MANOS), which observes small, newly discovered NEOs. She also led the investigation of the observability of NEOs with the upcoming James Webb Space Telescope (JWST). Dr. Emery uses the same techniques to study silicate mineralogy and volatile compositions of near-Earth asteroids as described above for Main Belt and Trojan asteroids.
Thermophysical Characterization of Planetary Surfaces
Dr. Emery observes small bodies across the Solar System in the thermal infrared (i.e., the heat emitted by the surfaces). These observations enable determination of sizes and albedos (a technique called radiometry). Detailed thermal observations also enable thermophysical characterization of the surfaces, which, in turn, provide a window into the physical structure of the surface (e.g., is it covered in fine regolith like the Moon, or more bouldery, such as the NEAs Bennu and Itokawa).
Planetary Surface Processes Accordion Closed
Fluvial and Aeolian Geomorphology
Rivers leave tell-tails signs on landscapes and are important indicators of volatile flow, sediment transport, and habitability. Dr. Burr studies the deposits left by ancient rivers on Mars. These deposits now form positive-relief ridges, due to erosion of the surrounding landscape by wind, and help us understand ancient Martian climate.
Dr. Burr also studies present day rivers on Titan, the largest satellites of Saturn. At 10 times Earth’s distance from the Sun, Titan has a very frigid surface, so that water exists only as ice. However, liquid nitrogen and methane –which are gases at Earth temperatures — flow as liquid on Titan, forming both rivers and lakes.
Mars Surface Investigations
Both Dr. Edwards and Dr. Salvatore are Participating Scientists on the Mars Science Laboratory Curiosity rover mission, where they are active in both surface investigations and rover operations. In addition, their work focuses on understanding martian surface composition and thermophysical properties using reflectance and emission spectroscopy.
Dr. Salvatore uses analog environments and landscapes on Earth to understand how the martian surface has evolved over geologic time. Specifically, his work in the Transantarctic Mountains has demonstrated how the martian surface has geochemically evolved even under cold and dry conditions.
Spacecraft Missions Accordion Closed
NASA’s DART (Double Asteroid Redirection Test) will impact the moon of the near-Earth binary asteroid Didymos. The mission is an important test of asteroid deflection through kinetic impact and is NASA’s first planetary defense mission. Dr. Thomas leads the DART observations working group. This group focuses on using ground-based telescopes to obtain more information about the Didymos binary system and the orbit of the moon in particular. This information is critical to the mission because the observations will be used to note the change in the orbit of the asteroid moon after the impact of DART. We need to have a very firm understanding of the pre-impact orbit to understand how much we’ve changed the orbit. The DART mission is being developed and led for NASA by the Johns Hopkins University Applied Physics Laboratory.
Dr. Emery leads the surface composition working group on NASA’s Lucy mission to explore the Trojan asteroids. The nature and origin of the Trojan asteroids, which share Jupiter’s orbit around the sun, remain elusive. Lucy will provide the first close-up view of this large population of primitive objects.
Mars Odyssey Thermal Emission Imaging System
Drs. Edwards and Salvatore use thermal infrared imaging data from the Mars Odyssey Thermal Emission Imaging System (THEMIS) to reveal the compositional and physical properties of the martian surface. These high resolution thermal infrared data reveal key information about Mars’ volcanic, weathering and alteration processes.
Mars Science Laboratory
Drs. Edwards and Salvatore use Mars Science Laboratory (Curiosity) rover data to help constrain past and present environments on Mars in unprecedented detail. In addition to helping plan the rover activities, scientific investigations include studies that link orbital data to ground truth, detailed geochemical and mineralogical comparisons as well as earth analog studies.
Near Earth Object Surveyor Mission
Dr. Emery is on the investigation team of the NEO Surveyor Mission, a planned thermal infrared space telescope designed to discover and characterize near-Earth objects.
Drs. Emery, Thomas, and Edwards work on NASA’s OSIRIS-REx mission to return samples from the near-Earth asteroid Bennu. Characterizing the geology, geophysics, composition, and thermal properties of the surface with spacecraft data enables sample site selection, establishes context for laboratory analyses of returned samples, and provides the first detailed picture of the nature of small asteroids. Dr. Emery leads the thermal analysis working group, which is responsible for analysis of thermal data returned by the two spectrometers.