Department News

Postdoctoral Research Associate Alexandre Emsenhuber began working at LPL with Professor Erik Asphaug in February 2018. Alexandre's research focuses on collision processes and linking them with orbital dynamics. Collisions between similar-size bodies often leave multiple remnants. By tracking the remnants, Alexandre aims to determine realistic return scenario, when the remnants further collide or are ejected from the system. Alexandre also has an interest in modeling of giant planet formation by using an approach that combines accretion of solids, gas, orbital migration and dynamical interactions. With this method, he can assess the interactions between the different processes involved in the formation of those planets.

Alexandre grew up in Neuchâtel (Switzerland) where he obtained a B.S. in Physics in (2011). He earned his M.S. and Ph.D. from the University of Bern with Professor Willy Benz (2017). Alexandre's doctoral research was on impact processes occurring during the formation of planetary systems. He analysed collisions between protoplanets found in theoretical models of planetary formation and modeled specific events that could lead to planetary-scale features, such as the Martian borealis basin. In his free time, Alexandre likes to bike, hike, ski and cook.

Dave Horvath joined LPL in September 2017 as a Postdoctoral Research Associate working with Associate Professor Jeff Andrews-Hanna. His current research focuses on mapping and characterizing what is potentially the youngest volcanic eruption on Mars, a putative pyroclastic deposit in the Elysium Planitia region. He is also interested in the hydrology and ancient climate of Mars. His future work will focus on using hydrologic models and observations from the Mars Science Laboratory on the Curiosity rover to further constrain the evolution of the climate and hydrology of Gale crater and, by extension, Mars.

Dave was raised in Austin, Texas, and did his undergraduate down the road in San Antonio, earning a B.S. in Physics and a B.A. in Mathematics (2011) from St. Mary’s University. From there, Dave moved to Golden, Colorado, to study at the Colorado School of Mines, where he received his Ph.D. in Geophysics (2017). His thesis research was focused on characterizing the methane-based hydrological cycle of Titan and investigating the hydrology of Gale crater during the later stages of hydrologic activity. In his free time, Dave enjoys traveling and hiking, climbing—he's summited 14 of the 53 fourteen-thousand foot peaks in Colorado during his stint in Golden—but as an avid board gamer, he also enjoys a relaxed night of sitting around the game table with friends.

by Shane Byrne

This semester we returned to Death Valley after a gap of five years (not coincidently, the graduate student turnover timescale!).

Recent flood damage within the park provided the impetus needed to mix up some of the sites we stopped and camped at. Dante’s View is a great place to see the valley (from the east), but then again, so is Aguereberry Point (from the west). It was at this latter location that we really kicked off our tour of the valley and the closely-packed geological wonders it contains.

A favorite of hydrology students everywhere is the diversion of the enormous Furnace Creek wash through the relatively tiny Gower Gulch. This 1941 engineering adventure led to huge amounts of erosion as the drainage system struggled to return to something approaching equilibrium. All that eroded material goes somewhere—unfortunately it’s dumped on the main park highway, which the park service now bulldozes clear regularly. There’s been clearly visible erosion even since we visited in 2012. Only a small plug of bedrock now separates the main Furnace Creek wash and Gower’s Gulch. Once that goes, the erosion rate will rapidly spike as the Furnace Creek sediment empties en masse through Gower’s Gulch. Sadly, route 190 sits on top of this sediment and so its continued existence hangs by a geological thread. Although an impending logistical disaster for the park, the readjustment of the hydrological system is fascinating for us to watch.

There are few places in the world where so much diverse geology is crammed into such a small area. Dune fields, mud flows, breccia conglomerates, steam explosion craters, old lake shorelines, salt polygons and salt weathered boulders were all on our itinerary are just a sample of what is available. Some things like the sliding rocks of Racetrack Playa can be seen in very few locations and that was well worth the bone-jarring hours of driving it took to get there.

Trips like these are always bonding experiences for us especially when we get to set tents up in 50 mph winds in a dust storm as happened one night. However, several broken tents later we had the ample compensation of a hot meal and good company at the Badwater Saloon!

LPL extends best wishes to Joe Gotobed, retiring in June after many years of service to the department. Joe began his career at LPL in 1980 as a Programmer III. He has held a variety of titles through the years, retiring as Information Technology Manager, Principal. For nearly 40 years, Joe has been the "go-to" guy for computing at LPL. In the early 1980s, Joe designed and helped build the Kuiper datacenter and network from the ground up. He managed LPL computing's infrastructure through three decades of growth and technological evolution, from the days of punched cards to today's cloud computing. From Pioneer to OSIRIS-REx, Joe's contributions to networking and computing have been an integral part of LPL's success in solar system exploration. 

The recipient of this year's University of Arizona Billy Joe Varney Award for Excellence is Heather Enos, Deputy Principal Investigator for OSIRIS-REx. This award recognizes Heather's service to UA employees, attention to diversity, and community outreach efforts. Congratulations, Heather!

Congratulations, Sharon Hooven and Guy McArthur!

Sharon Hooven is the recipient of the 2018 LPL Outstanding Classified Staff Award.

Sharon joined LPL in August 2011 as a Senior Business Manager for OSIRIS-REx. She is responsible for ensuring compliance for mission contract requirements, which often requires long hours, including late evenings and weekends, to ensure deadlines are met and urgent subcontract modifications are completed. She has generated dozens of subcontracts and works with University of Arizona (UA) contracting office to ensure that university policies are also compliant, which benefits all UA contracts, not just those for OSIRIS-REx. Sharon was instrumental in establishing the Earned Value Management system required by the OREx contract. She is cited for her dedication, attention to detail, and outstanding service to students, staff, and faculty. Sharon plans to retire sometime in the fall (2018) and looks forward to traveling and catching up with friends and family.

Guy McArthur is the recipient of the 2018 LPL Appointed Personnel Award.

Guy is a Data Applications Developer with HiRISE. He was first hired as a student in 1993, transitioning to staff in 2001 as a Systems Programmer. Guy is responsible for HiRISE web applications, including HiReport, the web-based front end for all the data access and reporting needs of the science team, and HiWish, the public target suggestion system. He is currently developing a similar system for the team operating the University of Bern’s CaSSIS instrument aboard the ExoMars Trace Gas Orbiter, part of ESA’s Mars exploration program.  HiReport and HiWish are highly valued by the science team and the public. Guy is committed to being at the forefront of software development technology and practices, improving overall efficiency by introducing industry standards and tools for project management and software issue tracking (e.g., git, Java build and distribution systems) that expedite the building, testing, and release of software. Being ahead of the curve means that Guy proactively researches and communicates new technologies permitting "drop-in" solutions.  Guy’s nominators describe him as a quiet and unassuming team member, but one who is highly deserving of recognition for his outstanding work.

The PTYS 554 class (Evolution of Planetary Surfaces) explored the geology of northern Arizona.

LPL's planetary geology class conquers S P Crater, a 50,000 year old cinder cone north of Flagstaff (photo: Shane Byrne)

How would the world respond to the late discovery that an object was on a possible collision course with the Earth? How rapidly could we confirm its orbit to assess the likelihood of a collision and range of locations where it may occur? Could we determine its size, rotation state, and composition in order to quantify the threat posed? Would we have enough time to develop a response on the ground to minimize the threat to life and other assets? Students in this semester's offering of PTYS 416/516 (Asteroids, Comets and Kuiper Belt Objects) had the opportunity to consider these questions and to participate in the TC4 Observational Campaign, a global effort sponsored by the NASA Planetary Defense Coordination Office. 

Beginning last July, a global consortium of astronomers began tracking the asteroid 2012 TC4, a small asteroid predicted to have a close encounter with Earth on October 12, 2017. The LPL member of the TC4 project, Assistant Professor Vishnu Reddy, was tasked with obtaining spectral information from TC4 during the close approach period using the NASA IRTF. Recognizing the wider opportunity this event provided, he teamed with Associate Professor Walt Harris, with whom he was co-teaching the 416/516 course, to put together a class project related to this event. For this, the class was divided into two groups with separate responsibilities. The undergraduates in the course were given the task of following TC4 using the new RAPTORS telescope on the roof of the Kuiper Building. The graduate students, accompanied by professors Harris and Reddy, would travel to the big Island of Hawaii, where they would be directly involved in the IRTF observations, a trip underwritten by the LPL External Board of Advisors.

On October 7, the graduate team of 11 students arrived in Hilo, Hawaii, for the IRTF observations. On their way to Mauna Kea, they made a side trip to Volcanoes National Park, where they toured recent lava flows and were treated to a presentation on the ongoing HI-SEAS Mars mission simulation project. They also were given a guided tour of the observing process by Bobby Bus, the Deputy Director of the IRTF. With his help, the students were able to obtain a precursor spectroscopic measurement of TC4 from the remote observing site at the Institute for Astronomy in Hilo. The next day, they began their ascent of Mauna Kea, stopping first at the Hale Pohak–Onizuka center at an altitude of 9200 ft, where they would spend time adapting to reduced oxygen levels before making a "test" ascent to the IRTF at 13675 ft. During the test run, the students toured the telescope and followed along as the operator managed a nightly target list.

For the evening of the scheduled TC4 observations, the group was divided into two shifts. The first shift went to the summit near sunset with Professor Reddy, where they began making calibration observations. Down at Hale Pohaku, Professor Harris was waiting with a second group scheduled to go to the telescope at 8:30 p.m. where they would manage the second half of the observing program. Just as the second team was assembling to head to the summit, Hale Pohaku, along with every telescope on the mountain, was plunged into darkness by a power outage. The students at the summit quickly became involved in the effort to protect the telescope by closing the mirror covers and the dome. Once power was restored (2 hours later), the operators worked furiously to recover the computer control systems, reset control of the telescope, and to restart the focal plane instruments, but were unable to complete these tasks in the small window of opportunity that remained for observing TC4. During this time, the students were active in documenting the steps taken, providing a valuable record of the event.

Back in Tucson, the undergraduate team had assembled in the roof observatory in the Kuiper building to observe TC4. RAPTORS was not formally part of the global effort, and had only been commissioned a few months earlier. However, the student group was well prepared, having completed several nights of test observations looking at other asteroids. Their goal was to acquire TC4 and obtain a sequence of observations to be used for refining its measured 13-minute rotation period. This was a difficult task given the very low brightness of the object and its rapid motion against the background stars, and it meant that real time confirmation of the presence of the asteroid was not possible in every image they took. Working from a targeting ephemeris, they followed the expected location of the asteroid for more than two hours. Subsequent processing of the images they obtained showed that they were able to detect TC4 and track it across the sky.

The project achieved its goals of giving students the opportunity to be involved in a hands-on research project while also obtaining measurements to be used as part of the wider effort to characterize TC4. While the graduate student team was not able to obtain an IRTF spectrum on the night the students were present at the observatory, the data they obtained during remote observations 2 nights earlier meant that they did not return empty handed. They also gained new insight into the challenges and frustrations that come with groundbased observing, and their assistance during the power outage will be useful for optimizing the IRTF recovery process in the future. The undergraduate team had a successful observing run made possible through their own careful preparation, and provided the side benefit of obtaining observations that will prove useful for characterizing the RAPTORS telescope performance. As Haris Niazi, a member of the graduate student team, summed up the entire experience, “It was wonderful being part of something that takes you out of the familiar confines of a classroom and pits you against a real-world research problem. Observing was quite the experience.”

---

The Royal Museums Greenwich web site (Oct. 19, 2017) features a blog post by Adam De Salle, a student at John Roan School (Whitaker's high school). Adam hoped that the post would have coincided not only with the anniversary of Ewen's passing, but also, fittingly, with United Nations World Space Week, Vice President Pence's address to the National Space Council (regarding a return to the Moon), and the 60th anniversary of the launch of Sputnik 1. Adam writes that, "the primary objective of garnering some hometown recognition of this wonderful man's achievements has been somewhat accomplished." 

by Christopher Hamilton

Field trip participants: Ali Bramson, Laci Brock, Saverio Cambioni, Indujaa Ganesh, Anthony Garnello, Christopher Hamilton (Instructor), Tad Komacek, Daniel Lo, Patrick O'Brien, Sarah Peacock, Kyle Pearson, Laura Seifert, Joe Spitale (co-instructor), Maria Steinrueck, and Adam Sutherland.

During the Late Jurassic (~190 million years ago), what is now Arizona was a part of Pangaea, just as it was beginning to rift apart. At the time, northern Arizona was located near the equator at about 10°N. However, the region was far from being lush. Located in the "rain shadow" of the Central Pangaean Mountains, the region was part of vast "sand sea," called an erg. The erg covered 625,000 square kilometers and was characterized by enormous dunes, similar to those now found within the much smaller Namib Sand Sea, Sahara and Gobi Deserts. Dominantly formed through processes of wind-borne (aeolian) sediment transport, the sand sea developed into a nearly 700 m-thick red cross-bedded sandstone deposit, called the Navajo Sandstone Formation.

For fall 2017, LPL field trip students traveled to the Page region of northern Arizona to obtain a closer look at the Navajo Sandstone Formation, to learn more about their origin, and to discover how they have been modified since the break-up on Pangaea. On October 6, the LPL group drove to Page, via Flagstaff, stopping at the Sunset Crater National Monument and hiking to the top of Lenox Crater to view the San Francisco Peaks. The region includes over 600 volcanoes emplaced over the past 6 million years; the youngest of these volcanoes, Sunset Crater, formed less than 1000 years ago. From there, the group continued on to Page and the field trip focused mainly on exploring the Navajo Sandstone Formation within two cross-sections provided by the Colorado River Gorge and the Water Holes Canyon.

The next day, the LPL group had an opportunity to travel from the Glen Canyon Dam to Lees Ferry by taking a river raft along the Colorado River. From the water, the towering walls of the gorge rose up over 300 m, provided an exceptional view into the stratigraphy as well as tectonic history of the Navajo Sandstone Formation. The rafting trip also enabled students to stop along the way to see Native American petroglyphs carved thousands of years ago into dark "desert varnish" on the rocks. On the drive back to Page, the group stopped at the Horseshoe Bend overlook to present their research on the geologic history of the region and the processes that lead to the formation of the Navajo Sandstone Formation and more recent Colorado River.

With this perspective, students were able to spend the following day exploring the Water Holes Canyon, which serves as an ephemeral tributary to the Colorado River. Much like the famous Antelope Canyon, the Water Holes Canyon trail winds its way through impressive slot canyons carved into the Navajo Sandstone Formation. In this setting, students shared their presentations related to the geological and ecological characteristics of the region as well as eolian and aqueous processes. The group also developed their observational skills by making geological sketches in their field books and measuring the orientations of bedding planes, unconformities, and faults. On the way back to Tucson, late in the afternoon on October 9, the group stopped outside Cameron to see the remains of a reclaimed uranium mine and discuss aspects of economic geology and its effects on the region.

This focused field trip provided a deeper look at the Navajo Sandstone Formation and its place within the "Grand Staircase," which is an exceptional stratigraphic succession exposed through the southwest United States. Additionally, students drew connections to other Earth-like and exotic planetary bodies like Mars and Titan, connecting the processes they observed to those operating on other worlds.

Water Holes Canyon trail providing exposures through Navajo Sandstone Formation (photo: Adam Sutherland)

---

Group photo on the Colorado River at Lees Ferry (photo: Christopher Hamilton)