Parallel Session 3: Lunar Geophysics & Magnetics Overview Talk

No abstract availabl

The Grizzly, December 3, 2009

Students Write Letters to Raise Money for St. Jude • Usernames Unlock Opportunities: UC Career Net Overview • Introducing the Ursinus Bioethics Society • Tuition Increases to Stay Competitive and to Cut Back on State Debts • Savoring Beer: All it Needs is a Little Love • Ursinus Japan Club Makes One Thousand Paper Cranes • Opinion: Can Ex-Significant Others Ever Be Your New Close Friends? • Ursinus Men\u27s Basketball Wins Home Opener; Improves to 3-1https://digitalcommons.ursinus.edu/grizzlynews/1801/thumbnail.jp

The Grizzly, March 25, 2010

27th Annual Airband Benefits Dignity House • Ursinus College Theater Presents The Elephant Man • Bank Robber Flees to Ursinus Campus Parking Lot • InterVarsity Group Travels to Camden Over Spring Break • Dangerous Risk to Multi-Tasking • Ursinus Field Hockey Intramurals are Open for Spring • UC Baseball Makes Best of Florida Trip • UC Alum Coaches Cornell to Sweet 16https://digitalcommons.ursinus.edu/grizzlynews/1809/thumbnail.jp

The Grizzly, February 25, 2010

Airband Date Auction Meets, Surpasses Goal • Drawing the Curtain Opens at the Berman Museum • Spread the Word to End the R Word Next Week • Student-Athlete Advisory Committee Takes UC Athletics Beyond the Fieldhouse • Snow Photos • Author Speaks on Campus About Bringing Nature Home • Skin We\u27re In Addresses Self-Esteem Issues • Cutting Down Waste by Recycling Kegs Instead of Canshttps://digitalcommons.ursinus.edu/grizzlynews/1807/thumbnail.jp

The Grizzly, February 4, 2010

The Brandon Kamin Show Premieres • Students Leading Haiti Relief Initiatives • Berman Premieres Min(d)ing the Landscape Exhibit • Ursinus Alumnus, J. D. Salinger, Dies • TCE Air Monitoring: Ursinus Student Research with the DEP • Learning to Learn: Choosing Majors and Finding a Path at Ursinus College • Opinion: Student Perceptions of CIE: What do Students Take from Course? • Ursinus Men\u27s Rugby Looking Forward to 2010https://digitalcommons.ursinus.edu/grizzlynews/1804/thumbnail.jp

High Resolution Images of Orbital Motion in the Trapezium Cluster: First Scientific Results from the MMT Deformable Secondary Mirror Adaptive Optics System

We present the first scientific images obtained with a deformable secondary mirror adaptive optics system. We utilized the 6.5m MMT AO system to produce high-resolution (FWHM=0.07'') near infrared (1.6 um) images of the young (~1 Myr) Orion Trapezium theta 1 Ori cluster members. A combination of high spatial resolution and high signal to noise allowed the positions of these stars to be measured to within ~0.003'' accuracies. Including previous speckle data (Weigelt et al. 1999), we analyze a six year baseline of high-resolution observations of this cluster. Over this baseline we are sensitive to relative proper motions of only ~0.002''/yr (4.2 km/s at 450 pc). At such sensitivities we detect orbital motion in the very tight theta 1 Ori B2B3 (52 AU separation) and theta 1 Ori A1A2 (94 AU separation) systems. Such motions are consistent with those independently observed by Schertl et al. (2003) with speckle interferometry, giving us confidence that these very small (~0.002''/yr) orbital motions are real. All five members of the theta 1 Ori B system appear likely gravitationally bound. The very lowest mass member of the theta 1 Ori B system (B4) has K' ~11.66 and an estimated mass of ~0.2 Msun. There was very little motion (4+/-15 km/s) detected of B4 w.r.t B1 or B2, hence B4 is possibly part of the theta 1 Ori B group. We suspect that if this very low mass member is physically associated it most likely is in an unstable (non-hierarchical) orbital position and will soon be ejected from the group. The theta 1 Ori B system appears to be a good example of a star formation ``mini-cluster'' which may eject the lowest mass members of the cluster in the near future. This ``ejection'' process could play a major role in the formation of low mass stars and brown dwarfs.Comment: To appear in the December 10, 2003 issue of the Astrophysical Journal 21 pages, 14 figures (some in color, but print OK in B&W

A Pre-Landing Assessment of Regolith Properties at the InSight Landing Site

This article discusses relevant physical properties of the regolith at the Mars InSight landing site as understood prior to landing of the spacecraft. InSight will land in the northern lowland plains of Mars, close to the equator, where the regolith is estimated to be ≥3--5 m thick. These investigations of physical properties have relied on data collected from Mars orbital measurements, previously collected lander and rover data, results of studies of data and samples from Apollo lunar missions, laboratory measurements on regolith simulants, and theoretical studies. The investigations include changes in properties with depth and temperature. Mechanical properties investigated include density, grain-size distribution, cohesion, and angle of internal friction. Thermophysical properties include thermal inertia, surface emissivity and albedo, thermal conductivity and diffusivity, and specific heat. Regolith elastic properties not only include parameters that control seismic wave velocities in the immediate vicinity of the Insight lander but also coupling of the lander and other potential noise sources to the InSight broadband seismometer. The related properties include Poisson’s ratio, P- and S-wave velocities, Young’s modulus, and seismic attenuation. Finally, mass diffusivity was investigated to estimate gas movements in the regolith driven by atmospheric pressure changes. Physical properties presented here are all to some degree speculative. However, they form a basis for interpretation of the early data to be returned from the InSight mission.Additional co-authors: Nick Teanby and Sharon Keda

Initial results from the InSight mission on Mars

NASA’s InSight (Interior exploration using Seismic Investigations, Geodesy and Heat Transport) mission landed in Elysium Planitia on Mars on 26 November 2018. It aims to determine the interior structure, composition and thermal state of Mars, as well as constrain present-day seismicity and impact cratering rates. Such information is key to understanding the differentiation and subsequent thermal evolution of Mars, and thus the forces that shape the planet’s surface geology and volatile processes. Here we report an overview of the first ten months of geophysical observations by InSight. As of 30 September 2019, 174 seismic events have been recorded by the lander’s seismometer, including over 20 events of moment magnitude Mw = 3–4. The detections thus far are consistent with tectonic origins, with no impact-induced seismicity yet observed, and indi- cate a seismically active planet. An assessment of these detections suggests that the frequency of global seismic events below approximately Mw = 3 is similar to that of terrestrial intraplate seismic activity, but there are fewer larger quakes; no quakes exceeding Mw = 4 have been observed. The lander’s other instruments—two cameras, atmospheric pressure, temperature and wind sensors, a magnetometer and a radiometer—have yielded much more than the intended supporting data for seismometer noise characterization: magnetic field measurements indicate a local magnetic field that is ten-times stronger than orbital estimates and meteorological measurements reveal a more dynamic atmosphere than expected, hosting baroclinic and gravity waves and convective vortices. With the mission due to last for an entire Martian year or longer, these results will be built on by further measurements by the InSight lander

Soccer-Specific Fatigue and Eccentric Hamstrings Muscle Strength

Epidemiologic findings of higher incidences of hamstrings muscle strains during the latter stages of soccer match play have been attributed to fatigue. To investigate the influence of soccer-specific fatigue on the peak eccentric torque of the knee flexor muscles. Descriptive laboratory study. Controlled laboratory environment. Ten male professional soccer players (age = 24.7 ± 4.4 years, mass = 77.1 ± 8.3 kg, ... = 63.0 ± 4.8 mL*kg^sup -1^-min^sup -1^). Participants completed an intermittent treadmill protocol replicating the activity profile of soccer match play, with a passive halftime interval. Before exercise and at 15-minute intervals, each player completed isokinetic dynamometer trials. Peak eccentric knee flexor torque was quantified at isokinetic speeds of 180°*s^sup -1^, 300°*s^sup -1^, and 60°*s^sup -1^, with 5 repetitions at each speed. Peak eccentric knee flexor torque at the end of the game (T^sub 300eccH105^ = 127 ± 25 Nm) and at the end of the passive halftime interval (T^sub 300eccH00^ = 133 ± 32 Nm) was reduced relative to T^sub 300eccH00^ (167 ± 35 Nm, P < .01) and T^sub 300eccH15^ (161 ± 35 Nm, P = .02). Eccentric hamstrings strength decreased as a function of time and after the halftime interval. This finding indicates a greater risk of injuries at these specific times, especially for explosive movements, in accordance with epidemiologic observations. Incorporating eccentric knee flexor exercises into resistance training sessions that follow soccer-specific conditioning is warranted to try to reduce the incidence or recurrence of hamstrings strains. (Note: Some of the scientific symbols can not be represented correctly in the abstract. Please read with caution and refer to the original publication.