766 research outputs found
Basin and Crater Ejecta Contributions to the South Pole-Aitken Basin (SPA) Regolith; Positive Implications for Robotic Surface Samples
The ability of impacts of all sizes to laterally transport ejected material across the lunar surface is well-documented both in lunar samples [1-4] and in remote sensing data [5-7]. The need to quantify the amount of lateral transport has lead to several models to estimate the scale of this effect. Such models have been used to assess the origin of components at the Apollo sites [8-10] or to predict what might be sampled by robotic landers [11-13]. Here we continue to examine the regolith inside the South Pole-Aitken Basin (SPA) and specifically assess the contribution to the SPA regolith by smaller craters within the basin. Specifically we asses the effects of four larger craters within SPA, Bose, Bhabha, Stoney, and Bellinsgauzen all located within the mafic enhancement in the center of SPA (Figure 1). The region around these craters is of interest as it is a possible landing and sample return site for the proposed Moon-Rise mission [14-17]. Additionally, understanding the provenance of components in the SPA regolith is important for interpreting remotely sensed data of the basin interior [18-20]
Identificación de las características morfológicas relacionadas con la estabilidad del rendimiento de arroz en dos regiones de Colombia
Documenting of Geologic Field Activities in Real-Time in Four Dimensions: Apollo 17 as a Case Study for Terrestrial Analogues and Future Exploration
During the Apollo exploration of the lunar surface, thousands of still images, 16 mm videos, TV footage, samples, and surface experiments were captured and collected. In addition, observations and descriptions of what was observed was radioed to Mission Control as part of standard communications and subsequently transcribed. The archive of this material represents perhaps the best recorded set of geologic field campaigns and will serve as the example of how to conduct field work on other planetary bodies for decades to come. However, that archive of material exists in disparate locations and formats with varying levels of completeness, making it not easily cross-referenceable. While video and audio exist for the missions, it is not time synchronized, and images taken during the missions are not time or location tagged. Sample data, while robust, is not easily available in a context of where the samples were collected, their descriptions by the astronauts are not connected to them, or the video footage of their collection (if available). A more than five year undertaking to reconstruct and reconcile the Apollo 17 mission archive, from launch through splashdown, has generated an integrated record of the entire mission, resulting in searchable, synchronized image, voice, and video data, with geologic context provided at the time each sample was collected. Through www.apollo17.org the documentation of the field investigation conducted by the Apollo 17 crew is presented in chronologic sequence, with additional context provided by high-resolution Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera (NAC) images and a corresponding digital terrain model (DTM) of the Taurus-Littrow Valley
What Do Nectaris Basin Impact Melt Rocks Look like and Where Can We Find Them?
The formation of the Nectaris basin is a key event defining the stratigraphy of the Moon. Its absolute age, therefore, is a linchpin for lunar bombardment history. Fernandes et al. gave a thorough account of the history of different samples thought to originate in Nectaris, with the upshot being there is little agreement on what samples represent Nectaris, if any. We are revisiting the effort to identify Nectaris basin impact-melt rocks at the Apollo 16 site, to model their emplacement, and to use these parameters to examine other sites where Nectaris impact melt is more abundant and/or more recognizable for potential further study
SPACE TELESCOPE SCIENCE
We present the results and measurement of Charge Transfer Efficiency (CTE) of the WFC3 UVIS detector, based on data acquired during the monthly internal Extended Pixel Edge Response (EPER) observations over a 2 year period. We present an algorithm for CTE assessment and fit a power-law to CTE measures versus signal level. We find that at each signal level, CTE declines linearly over time and CTE losses are worst at the lowest signal levels. 1
Record-setting Cosmic-ray Intensities in 2009 and 2010
We report measurements of record-setting intensities of cosmic-ray nuclei from C to Fe, made with the Cosmic Ray Isotope Spectrometer carried on the Advanced Composition Explorer in orbit about the inner Sun-Earth Lagrangian point. In the energy interval from ~70 to ~450 MeV nucleon^(–1), near the peak in the near-Earth cosmic-ray spectrum, the measured intensities of major species from C to Fe were each 20%-26% greater in late 2009 than in the 1997-1998 minimum and previous solar minima of the space age (1957-1997). The elevated intensities reported here and also at neutron monitor energies were undoubtedly due to several unusual aspects of the solar cycle 23/24 minimum, including record-low interplanetary magnetic field (IMF) intensities, an extended period of reduced IMF turbulence, reduced solar-wind dynamic pressure, and extremely low solar activity during an extended solar minimum. The estimated parallel diffusion coefficient for cosmic-ray transport based on measured solar-wind properties was 44% greater in 2009 than in the 1997-1998 solar-minimum period. In addition, the weaker IMF should result in higher cosmic-ray drift velocities. Cosmic-ray intensity variations at 1 AU are found to lag IMF variations by 2-3 solar rotations, indicating that significant solar modulation occurs inside ~20 AU, consistent with earlier galactic cosmic-ray radial-gradient measurements. In 2010, the intensities suddenly decreased to 1997 levels following increases in solar activity and in the inclination of the heliospheric current sheet. We describe the conditions that gave cosmic rays greater access to the inner solar system and discuss some of their implications
Із джерелознавчої спадщини: маловідома стаття Михайла Тележинського«Микола Лисенко»
У статті проаналізовано маловідому публікацію композитора з Волині Михайла Тележинського про основоположника української класичної музики Миколу Лисенка (1842–1912). Вперше впроваджується до сучасного наукового обігу матеріал, опублікований в часописі «Церква і нарід» від 15 жовтня 1937 року, Ч. 20.Unknown article about a founder of Ukrainian classic music Mykola Lysenko by Mykhajlo Telezhynsky, composer from Volyn Region, is examined. This information published in newspaper «Церква і нарід» («Church and people») on October, 15, 1937, is improved to modern scholar usage at the first time
The optical counterpart to gamma-ray burst GRB970228 observed using the Hubble Space Telescope
Although more than 2,000 astronomical gamma-ray bursts (GRBs) have been
detected, and numerous models proposed to explain their occurrence, they have
remained enigmatic owing to the lack of an obvious counterpart at other
wavelengths. The recent ground-based detection of a transient source in the
vicinity of GRB 970228 may therefore have provided a breakthrough. The optical
counterpart appears to be embedded in an extended source which, if a galaxy as
has been suggested, would lend weight to those models that place GRBs at
cosmological distances. Here we report the observations using the Hubble Space
Telescope of the transient counterpart and extended source 26 and 39 days after
the initial gamma-ray outburst. We find that the counterpart has faded since
the initial detection (and continues to fade), but the extended source exhibits
no significant change in brightness between the two dates of observations
reported here. The size and apparent constancy between the two epochs of HST
observations imply that it is extragalactic, but its faintness makes a
definitive statement about its nature difficult. Nevertheless, the decay
profile of the transient source is consistent with a popular impulsive-fireball
model, which assumes a merger between two neutron stars in a distant galaxy.Comment: 11 pages + 2 figures. To appear in Nature (29 May 1997 issue
Recent Results from the Lunar Reconnaissance Orbiter Mission and Plans for the Extended Science Phase
The Lunar Reconnaissance Orbiter spacecraft (LRO), launched on June 18, 2009, began with the goal of seeking safe landing sites for future robotic missions or the return of humans to the Moon as part of NASA's Exploration Systems Mission Directorate (ESMD). In addition, LRO's objectives included the search for surface resources and to investigate the Lunar radiation environment. After spacecraft commissioning, the ESMD phase of the mission began on September 15, 2009 and completed on September 15, 2010 when operational responsibility for LRO was transferred to NASA's Science Mission Directorate (SMD). The SMD mission was scheduled for 2 years and completed in September, 2012. The LRO mission has been extended for two years under SMD. The extended mission focuses on a new set of goals related to understanding the geologic history of the Moon, its current state, and what it can tell us about the evolution Of the Solar System. Here we will review the major results from the LRO mission for both exploration and science and discuss plans and objectives going forward including plans for the extended science phase out to 2014. Results from the LRO mission include but are not limited to the development of comprehensive high resolution maps and digital terrain models of the lunar surface; discoveries on the nature of hydrogen distribution, and by extension water, at the lunar poles; measurement of the day and night time temperature of the lunar surface including temperature down below 30 K in permanently shadowed regions (PSRs); direct measurement of Hg, H2, and CO deposits in the PSRs, evidence for recent tectonic activity on the Moon, and high resolution maps of the illumination conditions as the poles. The objectives for the second and extended science phases of the mission under SMD include: 1) understanding the bombardment history of the Moon, 2) interpreting Lunar geologic processes, 3) mapping the global Lunar regolith, 4) identifying volatiles on the Moon, and 5) measuring the Lunar atmosphere and radiation environment
Lunar International Science Coordination/Calibration Targets
A new era of international lunar exploration has begun and will expand over the next four years with data acquired from at least four sophisticated remote sensing missions: KAGUYA (SELENE) [Japan], Chang'E [China], Chandrayaan-l [India], and LRO [United States]. It is recognized that this combined activity at the Moon with modern sophisticated sensors wi II provide unprecedented new information about the Moon and will dramatically improve our understanding of Earth's nearest neighbor. It is anticipated that the blooming of scientific exploration of the Moon by nations involved in space activities will seed and foster peaceful international coordination and cooperation that will benefit all. Summarized here are eight Lunar International Science Coordination/Calibration Targets (L-ISCT) that are intended to a) allow cross-calibration of diverse multi-national instruments and b) provide a focus for training young scientists about a range of lunar science issues. The targets, discussed at several scientific forums, were selected for coordinated science and instrument calibration of orbital data. All instrument teams are encouraged to participate in a coordinated activity of early-release data that will improve calibration and validation of data across independent and diverse instruments
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