Seminars for Scientists

Spring 2016 Schedule:

1/7/2016 – Jan-Erik Wahlund; Heavy Metal – An ESA M5 mission to a metallic asteroid

Speaker:   Jan-Erik Wahlund (Swedish Institute of Space Physics)
Date & Time:   1/7/2016 ,  4:00 PM Location: SPSC N100


(16) Psyche is the largest known M-class asteroid (240 x 185 x 145 km), and a density of 5 – 8 g/cm(3) is inferred from orbit perturbations of nearby asteroids. Other ground observations suggest that the surface and dust around this object is iron-nickel rich with very little water. These observations are important considering the… Read more »

1/14/2016- Deanne Rogers; Understanding Early Martian Surface Processes and Environments through Visible and Infrared Mapping of the Ancient Highlands

Speaker:   A. Deanne Rogers (Stony Brook Univ.)
Date & Time:   1/14 ,  4:00 PM Location: SPSC W120


An important aspect of community-wide efforts to understand the geologic and climatic history of early Mars is to constrain the style(s) and timing of resurfacing events in the Noachian. The cratered plains of the ancient highlands exhibit diversity in compositional and thermophysical properties, providing some constraints on the resurfacing history and thus the processes and… Read more »

1/21/2016 – Brian Fleming; Lyman Alpha and Lyman Ultraviolet Emission from Stars and Galaxies – Instruments and Techniques for Science in the UV

Speaker:   Brian Fleming (LASP)
Date & Time:   1/21 ,  4:00 PM Location: SPSC W120


Low material transmission and reflection in the far-ultraviolet has posed a major constraint on astronomy in the observed-frame UV. The most prominent NASA observatory with sensitivity in the Lyman ultraviolet, FUSE, had limited angular resolution and high background equivalent flux introduced by the need to minimize reflections to maintain effective area. The spectroscopic imaging capabilities… Read more »

1/28/2016 – Leslie Young ; The Pluto system as seen by NASA’s New Horizons spacecraft

Speaker:   Leslie Young (SwRI)
Date & Time:   1/28 ,  4:00 PM Location: SPSC W120


When NASA’s New Horizons spacecraft flew past Pluto and its five moons last July, it revealed a beautiful, varied, and puzzling system.  Pluto’s surface ranges from dark and cratered terrains, to tall mountain ranges, to geologically young ice flows.  Charon sports a completely unexpected dark, reddish area near its north pole.  Pluto’s atmosphere is hazy… Read more »

2/4/2016- Bill Bottke; The Calm Before the Storm: Exploring the Post Accretionary Doldrums Prior to the Late Heavy Bombardment

Speaker:   Bill Bottke (SwRI)
Date & Time:   2/4 ,  4:00 PM Location: LSTB 299


The early bombardment of the inner solar system played a critical role in planetary evolution, but there is still considerable uncertainty about what happened when. Dynamical models suggest two major bombardment phases may have taken place: (i) a post-accretionary period where newly-formed worlds were struck by leftover planetesimals, and (ii) a late heavy bombardment period,… Read more »

2/11/2016- Cathy Olkin; Pluto’s Atmosphere and Surface Composition

Speaker:   Cathy Olkin (SwRI)
Date & Time:   2/11 ,  4:00 PM Location: SPSC W120


After traveling for more than 9 years, NASA’s New Horizons mission accomplished its prime objective – the initial reconnaissance of the Pluto system. On July 14, New Horizons passed about 12,500 km from Pluto’s surface, flying between Pluto and the orbit of Pluto’s large moon Charon.  The seven instruments on board the spacecraft include a… Read more »

2/18/2016- Ed Thiemann; A Lumped Element Thermal Model for the Cooling Phase of Solar Flares

Speaker:   Ed Thiemann (LASP)
Date & Time:   2/18 ,  4:00 PM Location: SPSC W120


Solar flares are the result of magnetic reconnection in the solar corona which converts magnetic energy into kinetic energy resulting in the rapid heating of solar plasma.  Characterizing how this hot plasma subsequently cools is important for understanding the evolution of flares and the corresponding heating of the quiescent corona.  Because the flare soft x-ray… Read more »

2/25/2016 – Jeannette Heiligers ; “Sailing on Sunlight” – solar sails for planetary science

Speaker:   Jeannette Heiligers (Univ. of Strathclyde)
Date & Time:   2/25 ,  4:00 PM Location: SPSC W120


The 21st of May 2010 saw the dawn of a new era in space propulsion when the Japanese Space Agency, JAXA, launched its IKAROS spacecraft. Twenty days into the mission, IKAROS unfurled a 14×14 m2 solar sail that would take the probe on a six-month voyage to Venus, propelled solely by the solar photons reflecting… Read more »

3/3/2016 – Tom Woods; Jack Eddy’s Study of the Maunder Minimum Inspires a Long Series of Satellite-Based Solar Irradiance Measurements: LASP and HAO solar irradiance projects between 1970 and 2010

Speaker:   Tom Woods (LASP)
Date & Time:   3/3 ,  4:00 PM Location: SPSC W120


What if Jack Eddy hadn’t rediscovered the work by Gustav Spörer and Edward W. Maunder about the period of few sunspots in the 17th century? Would there be much interest today in understanding the solar “constant”, or would there be robust observational programs in measuring the solar irradiance and its variability and studies about Sun-Climate?… Read more »

3/10/2016- Erik Richard; Long-term Measurements of Solar Spectral Irradiance: Lessons learned and the Path Forward

Speaker:   Erik Richard (LASP)
Date & Time:   3/10 ,  4:00 PM Location: SPSC N100


Accurate, long-term solar spectral irradiance (SSI) measurements are vital for interpreting how solar variability affects the balance of the Earth’s total energy budget and for validating climate model sensitivities to spectrally varying solar forcing. Ultimately, understanding these effects requires continuous measurements of SSI that meet the stringent requirements of climate-quality accuracy and stability over time…. Read more »

3/17/2016- Travis Metcalfe; Breaking Magnetic Braking in Sun-like Stars

Speaker:   Travis Metcalfe (SSI)
Date & Time:   3/17 ,  4:00 PM Location: SPSC N100


Precise photometry from the Kepler space telescope allows not only the measurement of rotation in solar-type field stars, but also the determination of reliable masses and ages from asteroseismology. These critical data have recently provided the first opportunity to calibrate rotation-age relations for stars older than the Sun. The evolutionary picture that emerges is surprising:… Read more »

3/24/2016- Jeremiah Sjoberg; Stratosphere-troposphere coupling insights from the Sudden Stratospheric Warming Compendium

Speaker:   Jeremiah Sjoberg (NOAA)
Date & Time:   3/24 ,  4:00 PM Location: SPSC W120


Sudden stratospheric warmings (SSWs) are first-order dynamical events in the polar winter stratosphere, which are known to influence tropospheric variability on medium range time scales of roughly 10-60 days. Here we present results from the development of a SSW compendium composed of processed data derived from six modern reanalysis products. The aim of this compendium… Read more »

3/28/2016 – Greg McFarquhar; Use of In-Situ Observations for Quantifying Ice Cloud Microphysical Properties and Processes, and their Uncertainties

Speaker:   Greg McFarquhar (U of Illinois)
Date & Time:   3/28 ,  3:00 PM Location: SPSC W120


Some of the most fundamental and complex problems in climate and weather research today are our poor understanding of the basic properties of clouds and our inability to determine quantitatively the many effects that clouds have on weather and climate. The representation of ice microphysical processes such as riming, sedimentation, aggregation, evaporation and deposition has… Read more »

3/31/2016- Lynn Wilson; Relativistic electrons produced by foreshock disturbances

Speaker:   Lynn Wilson (NASA GSFC)
Date & Time:   3/31 ,  4:00 PM Location: SPSC W120


Charged particles reflected and accelerated to suprathermal or even ultra relativistic energies by strong (i.e., high Mach number) astrophysical collisionless shock waves can stream away forming a foreshock region in communication with the shock.  Foreshocks — observed since the 1960s — are primarily populated by suprathermal ions (some contain relativistic particles) energized at or near… Read more »

4/7/2016 -Cesare Barbieri; From Giotto to Rosetta: 30 years of cometary science from Space

Speaker:   Cesare Barbieri (Univ. of Padova)
Date & Time:   4/7 ,  4:00 PM Location: SPSC W120


Thirty years ago, the 12th of March 1986, the European Giotto spacecraft flew by Comet Halley, obtaining the conclusive evidence that comets indeed have a nucleus. The series of images obtained by the Halley Multicolour Camera was abruptly interrupted when a cometary dust grain blew away its external structure (plane mirror and baffle), thus preventing… Read more »

POSTPONED- John Spencer; The Weird and Wonderful Geology of Pluto and its Moons

Speaker:   John Spencer (SwRI)
Date & Time:   TBD ,  4:00 PM Location: LSTB 299


In July 2015, the New Horizons mission gave us our first detailed view of the Pluto system after a 9.5 year journey from Earth.  New Horizons revealed that Pluto’s geology is complex and remarkably diverse.  Ancient cratered and fractured terrain is interrupted by much younger features that are likely active to the present day, including… Read more »

4/21/2016 – Sonal Jain; Mars’ atmosphere and its variability as observed by Imaging Ultraviolet Imaging Spectrograph onboard MAVEN.

Speaker:   Sonal Jain (LASP)
Date & Time:   4/21 ,  4:00 PM Location: SPSC W120


The Imaging Ultraviolet Spectrograph (IUVS) is one of nine science instruments aboard the Mars Atmosphere and Volatile and EvolutioN (MAVEN) spacecraft, whose payload is dedicated to exploring the upper atmosphere of Mars and understanding the magnitude and drivers of Mars’ atmospheric escape rate. IUVS uses ultraviolet light to investigate the lower and upper atmosphere and… Read more »

4/28/2016 – Stuart Robbins; Binary Topics for a Binary System: Why Craters Matter in the Pluto-Charon System, and Creating Visuals for Public Outreach for the New Horizons Flyby

Speaker:   Stuart Robbins (SwRI)
Date & Time:   4/28 ,  4:00 PM Location: SPSC N100


NASA’s New Horizons mission to the Pluto-Charon system has returned a wealth of data about these objects currently 33 AU from the sun.  Among those data are information about impact craters on four of these bodies.  Impact craters offer a glimpse into many exogenic and endogenic processes that have informed and are informing the science… Read more »

5/4/2016- Konrad Sauer; Current-driven Langmuir oscillations and wave packet formation in plateau plasmas: Relevance to type III bursts

Speaker:   Konrad Sauer (Univ. of Alberta)
Date & Time:   5/4 ,  11:00 AM Location: SPSC N100


Instead of starting with an unstable electron beam, the excitation of Langmuir waves is considered in the stable two-electron plasma after beam stabilization in which the velocity distribution function of the second population forms a plateau (p) with a more or less extended region of ¶fp/¶v=0. As shown by PIC simulations, this so-called plateau plasma… Read more »

5/5/2016 – Karly Pitman; Advances in Optical Constants For Space and Planetary Applications

Speaker:   Karly Pitman (SSI)
Date & Time:   5/5 ,  4:00 PM Location: SPSC W120


This talk will discuss the light scattering properties of different species of micron-scale dust particles and how to quantify their chemical composition and physical properties (e.g., size, shape, packing density or porosity of collections of grains) through a combination of radiative transfer modeling and laboratory analog spectroscopy at UV to IR wavelengths. The value of… Read more »

5/12/2016 – Sarah Gibson; Sun-Earth Connections: Magnetism across Time and Space

Speaker:   Sarah Gibson (UCAR)
Date & Time:   5/12 ,  4:00 PM Location: SPSC W120


Magnetic fields can seem like magic.  Indeed, the earliest uses of naturally-magnetic lodestones were for fortune telling, and to this day magnetism is a popular source of power for comic-book superheroes and supervillains alike.  The reality of magnetism is, if anything, more compelling.  It can affect the dynamics of stars and galaxies, but also how we live our daily lives. From the first use of… Read more »

5/19/2016 – Joshua Kammer; Stargazing from New Horizons: an Ultraviolet Solar Occultation of Pluto’s Atmosphere

Speaker:   Joshua Kammer (SwRI)
Date & Time:   5/19 ,  4:00 pm Location: SPSC W120


Not long after its closest encounter with Pluto last July, the Alice ultraviolet imaging spectrometer onboard New Horizons successfully observed spectral signatures of UV absorption by Pluto’s atmosphere during a solar occultation event. During this event, a UV bright star (more specifically, the Sun) passed behind Pluto as seen by the spacecraft, and the attenuated… Read more »