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Guest Speakers at UNL

Videos are provided below of presentations by guests of the UNL Astronomy Education Group over the past several years. YouTube and .mp4 versions are provided for most presentations. Some presentations have .ppt or .pdf versions available as well and we contend that running the YouTube version in one window and the slideshow in another is very advantageous.

The presentations are crudely classified as Astronomy (A), Education (E), and Technology (T).

“The Hidden Ocean of Europa: Exploring a Potentially Habitable World” A
Robert T. Pappalardo, Senior Research Scientist and Europa Study Scientist Jet Propulsion Laboratory, California Institute of Technology
April 15, 2014 (Multi-Departmental Colloquium)

Abstract:: Galileo spacecraft data suggest that a global ocean exists beneath the frozen ice surface of Jupiter’s moon Europa. Magnetometry data indicates an induced magnetic field at Europa, implying that a salt-water ocean exists today. A paucity of large craters argues for a surface on average only ~40–90 Myr, and two multi-ring structures suggest impacts punched through an ice shell ~20 km thick. Europa’s ocean and surface are inherently linked through tidal deformation of the floating ice shell, and tidal flexing and nonsynchronous rotation may generate stresses that fracture and deform the surface to create ridges and bands. Dark spots, domes, and chaos terrain are probably related to tidally driven ice convection, along with partial melting within the ice shell. Europa’s geological activity and probable direct contact between its ocean and rocky mantle may permit the chemical ingredients for life to be present within the ocean. Fascinating geology and geophysics, combined with high astrobiological potential, make Europa a top priority for future spacecraft exploration. The Europa Clipper is a mission concept currently being studied by NASA, which would make multiple flybys of Europa from Jupiter orbit, to investigate its potential habitability.



Link to Dr. Pappalardo's presentation (in pptx form)

Dr. Pappalardo's visit to UNL was made possible through the Harlow Shapley Visiting Lectureship Program of the American Astronomical Society


Link to Dr. Pappalardo's presentation (in ppt form).

Dr. Pappalardo's visit to UNL was made possible through the Harlow Shapley Visiting Lectureship Program of the American Astronomical Society

"Ices and Oceans in the Outer Solar System" A
Robert T. Pappalardo, Senior Research Scientist and Europa Study Scientist, Jet Propulsion Laboratory, California Institute of Technology
April 14, 2014 (Student Union Public Talk)

Abstract: On Earth, essentially everywhere there is liquid water, there is life, so it is reasonable that the search for extraterrestrial microbial life in our solar system focuses on the search for water. The solar system’s most promising candidate for a potentially habitable ocean beyond Earth lies beneath the surface of Jupiter’s ice-covered moon Europa, which is one of the most geophysically and astrobiologically fascinating and complex bodies in our solar system. Its exploration is key in advancing our understanding of habitable zones, in our solar system and beyond. Water oceans may also exist within other icy moons, including within Ganymede and Callisto at Jupiter, Enceladus and Titan at Saturn, and Triton at Neptune. We will take a tour of the solar system’s icy worlds that might contain watery oceans within. The interior oceans of icy worlds may be the most common habitats for life in the universe.

“The Smallest Free Particles in Saturn’s Rings” A
Dr. Rebecca Harbison, recent grad of Cornell University
February 31, 2014 (Jorgensen Hall Public Talk)

Abstract: The Cassini spacecraft, which entered orbit around Saturn in 2004, has provided a wealth of observations at resolutions and geometries unavailable from Earth, thereby expanding our knowledge of the Saturnian system. In particular, observations of Saturn’s rings not only give us an understanding both of this remarkable system, but a close look at the nearest debris disk to the Earth, offering insight into the behavior of these disks in an astrophysical context.

Cassini’s orbit about Saturn allows for solar occultations of the rings, a geometry impossible to achieve from Earth. During these occultations, the icy particles making up the rings diffract infrared light at angles detectable by the Visible‐Infrared Mapping Spectrometer (VIMS) instrument onboard, thus giving information about the size distribution of ring particles. Using VIMS, I have measured the minimum free ring particle size of the A and C Ring. While the C Ring result agrees with other studies, my observations of the A Ring show particles smaller than one millimeter, conflicting with previous results. However, I also discovered that including the A Ring’s self gravity wakes – temporary 50‐100 meter‐sized aggregates of ring particles – makes a noticeable difference in any attempt to model the ring’s particle‐size distribution,and previous studies did not account for this non‐homogenous ring structure.



(The .mp4 file for this presentation is 600 Mb in size and is available by e-mail request.)

Link to Dr. Harbison's presentation (in pdf form)


(direct link to the mp4 file, 172 MB)

"What do Successful Problem Solvers do when Solving Complex Problems?" E
Dr. Wendy Adams, University of Northern Colorado
October 26, 2013 (Astronomy Education Workshop Plenary)

Abstract: As part of our work to create a physics problem solving evaluation tool, we have undergone extensive studies to determine the scope and detail of what it is that experts do when solving problems. We have identified 44 separate skills within three major divisions - 1. knowledge, 2. beliefs, expectations and motivation and 3. processes - that are used when solving complex problems. We have also shown that a person's strengths' and weaknesses' when solving problems in everyday life are the same as in the physics classroom. Here we will describe the process of identifying these skills, categorization of these skills, studies validating their use in physics, and discuss implications for teaching.

Link to Dr. Adams' presentation (in pptx, in pdf).

"Invisible Galaxies" A
Dr. Beth Willman, Haverford College
October 26, 2013 (Astronomy Education Workshop Plenary)

Abstract: In the past five years, more than a dozen dwarf galaxies have been discovered around the Milky Way that are 100 times less luminous than any galaxy previously known, and a million times less luminous than the Milky Way itself. These objects are effectively invisible in images of the sky. Such ultra-faint galaxies provide a unique tracer of dark matter, and might also be the most numerous type of galaxy in the universe. This talk will focus on i. how astronomers can see invisible galaxies, ii. what invisible galaxies may teach us about dark matter, and iii. the roles that current and future sky surveys will play in the accessibility of this research to scientists and students at any type of institution. I will also highlight the contributions of undergraduates to invisible galaxy research at Haverford College.

Link to Dr. Willman's presentation (in pdf form)


(direct link to the mp4 file, 158 MB)

(direct link to the mp4 file, 150 MB)

"What is a Galaxy?" A E
Dr. Beth Willman, Haverford College
October 25, 2013 (Ruckman Dinner Presentation)

Abstract: The stars in our night sky belong to the Milky Way
galaxy. When we see a picture of a galaxy on TV or in a magazine, it is often a galaxy similar to how the Milky Way might instead appear from the outside: possessing beautiful spiral structure, with an easily visible conglomeration of stars, gas, and dust. Despite the impressions given by these typical depictions, the vast majority of the galaxies in the universe are puny dwarf galaxies much smaller and dimmer than the Milky Way. In fact, ~20 dwarf galaxies possessing only one millionth the number of stars in the Milky Way have recently been discovered. These discoveries have made astronomers question the very meaning of the word “galaxy”. This talk will highlight some basic history of astronomers’ understanding of galaxies, how computer simulations can help us understand galaxies, and how invisible galaxies are now guiding our understanding of what makes a galaxy, a galaxy.

Link to Dr. Willman's presentation (in pdf form)

Abstract: Since the discovery of the first Kuiper Belt object (KBO) in 1992 these objects have become key components to understanding the outer regions of our Solar System. Observations of both the dynamical and surface properties of these objects provide insight to the migration history of the giant planets. I will discuss various observational strategies for discovering and dynamically classifying KBOs and summarize our current understanding of the overall structure of the belt. Additionally, I will present the results from a compilation of studies on the colors (photometric properties), lightcurves and binary properties of sizable samples of KBOs in a variety of locations within the belt. Links between the dynamical and photometric properties of these objects may help to distinguish between various source populations and the range of conditions present in the protoplanetary disk.

Dr. Benecchi's visit was funded by the Jet Propulsion Laboratory's Outer Planets Colloquium Series.

Link to Dr. Benecchi's presentation slides (in pdf form).

"Solar System Archaeology: What we Learn from Small Bodies in our Solar System A
Dr. Susan Benecchi, Carnegie Instition of Washington and Planetary Science Institute
April 19, 2013 (Dept. of Physics & Astronomy Colloquium)

(direct link to the mp4 file, 158 MB)

"The New Horizons Mission: Pluto and Beyond" A
Dr. Susan Benecchi, Carnegie Instition of Washington and Planetary Science Institute
April 19, 2013 (Student Union Public Talk)

Dr. Benecchi's visit was funded by the Jet Propulsion Laboratory's Outer Planets Colloquium Series.

Link to Dr. Benecchi's presentation slides in .pdf form.

(direct link to the mp4 file, 178 MB)

Abstract:"The outermost region of the Solar System has yet to be explored by spacecraft. Pluto sits inside of the Kuiper Belt, a region of icy objects in the outer solar system that we believe is a relic of the Solar System's formation and evolution. The New Horizons (NH) spacecraft launched in January 2006, and will fly through the Pluto system in July 2015. We hope to visit a Kuiper Belt Object (yet to be identified) afterward, in the 2018-2020 timeframe. Since launch an additional four moons have been discovered orbiting Pluto. Instruments on the spacecraft will study the surfaces of Pluto and Charon with optical broadband and multicolor images to resolutions of a few hundred meters, as well as near-infrared spectral maps with a few kilometer resolution sensitive to volatiles such as water ice, methane ice and ammonia. We will also collect UV spectra and particle data sensitive to active volatile loss. I will present an overview of what we know about the Pluto system currently, the goals of the NH mission and our efforts to find a Kuiper Belt Object to visit after the Pluto system encounter.”

Abstract: Since 2003 we have been using the astronomical observing facilities at Luther College to observe the half-degree square field containing open star cluster M23 each clear night from February to October.  The work has resulted in approximately half a million images that have passed photometric quality tests from about 350 different nights.  The unprecedented temporal coverage of this data set allows us to search for apparent stellar variability on timescales from ranging from tenths of seconds to nearly a decade, including subtle or rare phenomena that might be missed otherwise.  We have confirmed variability in 58 of the approximately 1600 stars visible in the field.  The work has been the basis of more than 20 student/faculty collaborative projects.  In addition to our science goals we have goals for student learning ranging from the acquisition of specific techniques (e.g., statistical analysis tools) to a better appreciation of the way we achieve incremental growth in understanding the universe.  I will discuss our technique and results with a particular emphasis on the rewards and challenges of building an ongoing research project around individual student projects.

"Ten Years of Watching the Sky with Students" A E
Dr. Jeff Wilkerson, Luther College
October 6, 2012 (Astronomy Education Workshop Keynote)

(direct link to the mp4 file, 222 MB)

Unfortunately, the first few minutes of Jeff's presentation were lost due to technical difficulty.

"Our Dangerous Universe" A
Dr. Brian C. Thomas, Washburn University
October 5, 2012 (Ruckman Presentation)

Abstract: We live in a big, old, dangerous universe, on a planet that has seen many extinctions, several of them major. From asteroids to gamma-ray bursts, there are a variety of extra-terrestrial events that may have serious implications for life on Earth. I will start with a short introduction to our place in the universe and then discuss several potentially devastating events, how they would affect the Earth and how frequently they might occur.”

(direct link to the mp4 file, 234 MB)

Abstract: The value of in-class Internet technologies to student attentiveness, engagement, and learning remains both controversial and filled with promising potential. In this study, students were given the option to use LectureTools, an interactive suite of tools designed specifically for larger classes. The availability of these tools dramatically changed the mechanics of the course as more than 90 percent of students attending lecture voluntarily brought their laptops to class. On one hand, surveys over multiple semesters show that students believe the availability of a laptop is more likely to increase their time on tasks unrelated to the conduct of the course. On the other hand, the surveys also ascertained that students felt more attentive with the technology, significantly more engaged, and able to learn more with the technology than in similar classes without it. LectureTools also led to a dramatic increase in the number of students posing questions during class time, with more than half posing at least one question during class over the course of a semester, a percentage far higher than achieved in semesters prior to the use of this technology. These results suggest that while having laptops in the classroom can be a distraction to students, students of today show confidence that they are capable of productive multitasking, showing that they not only can handle this technology when applied through “deliberate engagement” using tools like LectureTools, but thrive with it, as seen through improved attentiveness, learning, and overall engagement even in larger classes.

"Making Big Classes Seem Small" E T
Dr. Perry Samson, University of Michigan
November 9, 2011 (Student Union Public Presentation)

(direct link to the mp4 file, 178 MB)
"The Science of Exoplanets" A
Dr. Jason Wright, Penn State University
October 22, 2011 (Astronomy Education Workshop Keynote)

Abstract: I will discuss the methods we use to detect exoplanets, and the sorts of planets we have detected so far, including planets in the so-called "Habitable Zone".  I will also discuss how recent discoveries have informed our theories of how planets like the Earth formed, and how abundant they are in the Universe.

(direct link to the mp4 file, 217 MB)

"Finding Supernovae" A
Dr.Travis Rector, University of Alaska
October 9, 2010 (Astronomy Education Workshop)

Abstract: A short presentation providing an overview of observing at Kitt Peak and making observations to detect novae in the Andromeda Galaxy.

(direct link to the mp4 file, 48 MB)

(The mov file for this presentation is 650 Mb and is available by e-mail request.)

"The Aesthetics of Astronomy" A T
Dr.Travis Rector, University of Alaska
October 8, 2010 (Ruckman Presentation)

Abstract: Modern telescopes, like the Hubble, generate stunning pictures of the Universe. How are these pictures generated? Why are they so beautiful? And are they real? As part of my talk I will describe how these telescopes work and how astronomers use the data from them for their research. I will also describe how the data are transformed into the beautiful color images we see. I will also discuss the authenticity of these images and why the images are so meaningful to us.

"Research-Based Science Education" A E
Dr.Travis Rector, University of Alaska
October 7, 2010 (UNL P&A Colloquium)

Most science classes are focused on teaching science content (e.g., Newton's Laws, phases of the moon) with the assessment primarily focused on how well they understand this content. As a result students don't understand the origins of this scientific knowledge. And it can lead to misconceptions about what scientists actually do. For example, students often think scientists are people who have simply memorized existing knowledge rather than being the ones who create new knowledge. To address this problem, we have developed a curriculum for "Astro 101" courses, where non-science, introductory level students learn science by doing authentic astronomical research projects. They analyze real data using authentic analysis tools to answer outstanding questions in modern astrophysical research. As part of my talk I will describe the curriculum, how it is implemented, and student gains as a result of participating.

(direct link to the mp4 file, 310 MB)
"Astronomy Demonstrations" A E
Dr. Dale Stille, University of Iowa, and Dr. Cliff Bettis, UNL
October 3, 2009 (Astronomy Education Workshop)

Abstract: Drs. Stille and Bettis present a wide variety of classroom demonstrations that illustrate astronomy related physics principles.

(The mov file for this talk is 670 Mb and is available by e-mail request.)

"Archeoastronomy for the Classroom" A E
Dr. Tyler Nordgren, University of Redlands
October 3, 2009 (Astronomy Education Workshop Keynote)

Abstract: In this presentation, Dr. Tyler Nordgren shows how archeoastronomy can be used to lead students into making their own observations of the sky, thereby reinforcing what they've learned in the classroom.

(direct link to the mov file, 100 MB)

(direct link to the mov file, 154 MB)

"Sky Above, Earth Below: Astronomy and the National Parks" A
Dr. Tyler Nordgren, University of Redlands
October 2, 2009 (Ruckman Presentation)

Abstract: The dark night skies over our nation’s national parks are fertile grounds for learning about the world of astronomy. The same environmental protections that maintain our wilderness on the ground also preserve the “wilderness” of a dark starry sky where the Milky Way can still be seen. Through direct “eyes-on” viewing opportunities in the park the public can learn about and appreciate current astronomical research. In addition, many of the geological formations our parks were built to protect are excellent examples of features and processes on other planets.

Abstract: This professional development seminar provides results from research into how the successful implementation of active engagement instructional strategies can improve students’ understanding beyond what is achieved by traditional instructional methods, even when used in the lecture portion of the science classroom.

From questioning in the classroom to small group collaborative activities, many forms of interactive teaching are modeled and discussed. Members of the Center for Astronomy Education (CAE) at the University of Arizona have been developing and conducting research on the effectiveness of learner-centered instructional strategies and materials that put students in an active role in the traditional lecture classroom. The results of this work have been incorporated into a series of “Teaching Excellence Workshops” that members of CAE have been conducting around the nation as part of the NASA Spitzer Education and Public Outreach Program, JPL Navigator/Exoplanet-Exploration Public Engagement Program and the NSF CCLI Phase III Collaboration of Astronomy Teaching Scholars (CATS) Program. The goal of these workshops is to improve participant’s implementation and pedagogical content knowledge of research-validated interactive learning strategies.

"Are You Really Teaching if No One is Learning?" E
Dr. Edward Prather, University of Arizona
September 25, 2009 (Student Union Public Presentation)

(direct link to the mov file, 239 MB)

"Chicken Little Was Right, the Sky IS Falling!" A
Dr. Terry Oswalt, Florida Institute of Technology
February 5, 2009 (Student Union Public Presentation)

(direct link to the mov file, 171 MB)

Abstract: Asteroids and comets may preserve the only records of the physical and chemical processes which marked the beginning of the solar system 4.6 billion years ago. Most asteroids revolve about the sun between the planets Mars and Jupiter and are believed to be the rocky remnants of the minor bodies from which all planets accrete. Comets are bodies that come from far outside the orbit of Pluto, in a dark realm called the Oort Cloud, a large icy debris zone which surrounds the Sun. Over the last decade, the risk of impacts from comets and asteroids has been recognized as substantial and a number of research programs have been undertaken to find and categorize the most dangerous Near Earth Objects (NEOs). Dr. Oswalt will discuss how NEOs are found, the way impact risks are assessed, what the effects of an impact can be, and how the human species might respond to the threat of a major impact.

Dr. Oswalt's visit to UNL was made possible through the Harlow Shapley Visiting Lectureship Program of the American Astronomical Society

"Citizen Science: From the Sky to Your Desktop" A E T
Dr. Pamela Gay, Southern Illinois University at Edwardsville
October 10, 2008

Abstract: Real science for the people, by the people, and of the sky. For well over 100 years, amateur astronomers have been making major contributions to the field of astronomy through backyard observations of the different classes of astronomical objects. Today, major contributions are being made by armchair astronomers working at their desks. In both cases, contributions by people like you have lead to Hubble Space Telescope observations and once in a lifetime discoveries. In this talk you'll learn about the science results coming out of the AAVSO, Galaxy Zoo, TransitSearch.org and other community collaborations.

(direct link to the mov file, 191 MB)

"Podcasting As Podteaching" A E T
Dr. Pamela Gay, Southern Illinois University at Edwardsville
October 10, 2008

Abstract: Technologies come and go, and the question is, do any of them actually facilitate real learning? In this talk Dr.Pamela L. Gay discusses ways to use podcasting that work, don't work, and how you do evaluation to make sense of it all.

(direct link to the mov file, 80 MB)