Near-infrared Spectroscopy of Near-Earth Asteroids PDF Download
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Author: Skylar S. Larsen
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
The near-infrared spectra of four near-Earth asteroids, 3122 Florence, (357439) 2004 BL86, 1036 Ganymed, and 4055 Magellan, were analyzed for traces of surface water. NEAs are widely thought to be the source of water and organics delivered to early Earth. Additionally, some NEAs are considered potentially hazardous objects (PHOs), and they could make threateningly close approaches to our planet. The Infrared Telescope Facility (IRTF), located at Mauna Kea, Hawaii, was used to measure long wavelength cross-dispersed (LXD) spectra of these four asteroids with SpeX mode. The measured spectra wavelength ranged from 1.67-4.2 [mu]m, which includes the 3-[mu]m feature attributed to water/hydroxyl. The 3[mu]m spectral feature was found on Florence, but not on 2004 BL86; meanwhile, the Ganymed and Magellan results were inconclusive. Discovering water on a celestial body such as Florence, an S-type asteroid, is highly unusual and warrants further study.
Author: Skylar S. Larsen
Publisher:
ISBN:
Category :
Languages : en
Pages : 0
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Book Description
The near-infrared spectra of four near-Earth asteroids, 3122 Florence, (357439) 2004 BL86, 1036 Ganymed, and 4055 Magellan, were analyzed for traces of surface water. NEAs are widely thought to be the source of water and organics delivered to early Earth. Additionally, some NEAs are considered potentially hazardous objects (PHOs), and they could make threateningly close approaches to our planet. The Infrared Telescope Facility (IRTF), located at Mauna Kea, Hawaii, was used to measure long wavelength cross-dispersed (LXD) spectra of these four asteroids with SpeX mode. The measured spectra wavelength ranged from 1.67-4.2 [mu]m, which includes the 3-[mu]m feature attributed to water/hydroxyl. The 3[mu]m spectral feature was found on Florence, but not on 2004 BL86; meanwhile, the Ganymed and Magellan results were inconclusive. Discovering water on a celestial body such as Florence, an S-type asteroid, is highly unusual and warrants further study.
Author: Nathanael Richard Wigton
Publisher:
ISBN:
Category :
Languages : en
Pages : 61
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Near-Earth asteroids (NEAs) are not expected to have H2O [water] ice on their surfaces because a) most accreted dry and therefore never contained H2O, and b) their relatively high surface temperatures should drive rapid H2O ice sublimation. However, OH/H2O has been detected on other anhydrous inner solar system objects, including the Moon and Vesta. Possible sources for OH/H2O in the inner Solar System might include production via solar wind interactions, carbonaceous chondrite or cometary impact delivery, or native OH/H2O molecules bound to phyllosilicates. As these processes are active in near-Earth space, detectable levels of OH/H2O might also be present on NEAs. OH/H2O can be detected by its absorption feature at wavelengths near 3 microns using near-infrared (2 - 4 microns) spectroscopy from ground-based infrared telescopes. Analysis of the shape of the 3-micron feature, coupled with the observed NEA orbital parameters and albedos, can help distinguish between the possible sources of OH/H2O. I used the SpeX instrument on NASA's Infrared Telescope Facility (IRTF) to measure spectra in from ~2 to 4 [mu]m[microns]. The study presented here uses 13 observations for 8 NEAs: (443) Eros (two observations), (1036) Ganymed (four observations), (3122) Florence, (54789) 2001 MZ7, (96590) 1998 XB, (285944) 2001 RZ11, (214088) 2004 JN13, (357439) 2004 BL86. The objects are split into two spectral groups based on band depth: No feature or shallow feature (
Author: National Academies of Sciences, Engineering, and Medicine
Publisher: National Academies Press
ISBN: 0309493986
Category : Science
Languages : en
Pages : 75
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Book Description
Near Earth objects (NEOs) have the potential to cause significant damage on Earth. In December 2018, an asteroid exploded in the upper atmosphere over the Bering Sea (western Pacific Ocean) with the explosive force of nearly 10 times that of the Hiroshima bomb. While the frequency of NEO impacts rises in inverse proportion to their sizes, it is still critical to monitor NEO activity in order to prepare defenses for these rare but dangerous threats. Currently, NASA funds a network of ground-based telescopes and a single, soon-to-expire space-based asset to detect and track large asteroids that could cause major damage if they struck Earth. This asset is crucial to NEO tracking as thermal-infrared detection and tracking of asteroids can only be accomplished on a space-based platform. Finding Hazardous Asteroids Using Infrared and Visible Wavelength Telescopes explores the advantages and disadvantages of infrared (IR) technology and visible wavelength observations of NEOs. This report reviews the techniques that could be used to obtain NEO sizes from an infrared spectrum and delineate the associated errors in determining the size. It also evaluates the strengths and weaknesses of these techniques and recommends the most valid techniques that give reproducible results with quantifiable errors.
Author: Committee on Planetary and Lunar Exploration
Publisher: National Academies Press
ISBN: 0309524075
Category : Science
Languages : en
Pages : 45
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Book Description
Comets and asteroids are in some sense the fossils of the solar system. They have avoided most of the drastic physical processing that shaped the planets and thus represent more closely the properties of the primordial solar nebula. What processing has taken place is itself of interest in decoding the history of our solar neighborhood. Near-Earth objects are also of interest because one or more large ones have been blamed for the rare but devastating events that caused mass extinctions of species on our planet, as attested by recent excitement over the impending passage of asteroid 1997 XF11. The comets and asteroids whose orbits bring them close to Earth are clearly the most accessible to detailed investigation, both from the ground and from spacecraft. When nature kindly delivers the occasional asteroid to the surface of Earth as a meteorite, we can scrutinize it closely in the laboratory; a great deal of information about primordial chemical composition and primitive processes has been gleaned from such objects. This report reviews the current state of research on near-Earth objects and considers future directions.Attention is paid to the important interplay between ground-based investigations and spaceborne observation or sample collection and return. This is particularly timely since one U.S. spacecraft is already on its way to rendezvous with a near-Earth object, and two others plus a Japanese mission are being readied for launch. In addition to scientific issues, the report considers technologies that would enable further advances in capability and points out the possibilities for including near-Earth objects in any future expansion of human exploration beyond low Earth orbit.
Author: Ellen Susanna Howell
Publisher:
ISBN:
Category : Asteroids
Languages : en
Pages : 186
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Book Description
The compositional distribution of asteroids provides clues to understanding solar system formation and evolutionary processes in the asteroid belt. The surface mineralogy and distribution of volatiles on asteroids is determined using visible and near-infrared spectroscopy. A revised asteroid taxonomy is developed which incorporates compositional information from the near-infrared asteroid spectra. A search is conducted for organic compounds on distant asteroids, thought to be most volatile-rich in composition. Our near-infrared spectroscopy of outer belt asteroids shows a trend of increasing red continuum slope with heliocentric distance. I interpret this trend as a compositional change, possibly due to increasing abundance of complex organic compounds on these more distant objects. I do not observe a CN absorption band near 2.2 $\mu$m, and conclude that the organics present are not primarily CN-bearing solids. The 3-$\mu$m water absorption band is not detected on distant D asteroids, but is seen on main belt D asteroids. This observation is consistent with the idea that D asteroids are volatile-rich, but the object must be heated in order to transform the silicates into hydrated minerals. No evidence of clay minerals is seen on any of the distant asteroids observed. The majority of the Jupiter Trojan asteroids have a uniform spectral appearance in spite of collisional processing, which implies that the dark red surface material is not a thin surface coating, but is representative of the bulk composition. Observations of near-Earth asteroids indicates a wide range of compositions, suggesting a variety of source regions. Two objects are detected which may contain hydrated minerals, a valuable resource in space. Three near-Earth asteroids are studied in detail, revealing a range of pyroxene chemistry and olivine content inconsistent with ordinary chondrite composition. The occurrence of spectral variability, and implied compositional inhomogeneity is approximately 20%.
Author: Janice L. Bishop
Publisher: Cambridge University Press
ISBN: 110718620X
Category : Language Arts & Disciplines
Languages : en
Pages : 655
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Book Description
Comprehensive overview of the spectroscopic, mineralogical, and geochemical techniques used in planetary remote sensing.
Author: Sean Ernest Marshall
Publisher:
ISBN:
Category :
Languages : en
Pages : 496
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Book Description
Chapter 1: Near-Earth asteroids are some of Earth's closest neighbors in space. Thousands are known, with dozens of new ones being discovered every week. Yet the physical characterization of near-Earth asteroids lags well behind discovery. Studying some asteroids in detail helps to reveal the properties of the overall population. This work focuses on the detailed characterization of a few specific near-Earth asteroids with high-quality data sets, particularly radar observations that can be used to determine their shapes and rotation states. Incorporating multiple types of observational data enables much better characterization than could be done with any single data set. Chapter 2: For (162421) 2000 ET70, incorporating lightcurves that had not been used for the modeling of Naidu et al. (2013) allows a better determination of its dimensions and rotation state. Incorporating infrared spectra further refines ET70's rotation state, since thermal modeling shows that some pole directions that provide good fits to the radar and lightcurve data are not compatible with the infrared observations. Thermal modeling also indicates that ET70's surface is heterogeneous, since no thermal model with uniform surface properties could provide an adequate fit to all of the infrared spectra. Chapter 3: (85989) 1999 JD6 was observed to have a large amplitude in visible and infrared lightcurves, suggesting that it is a highly elongated body. Radar images obtained during JD6's close approach in 2015 confirm this, revealing a contact binary with a maximum breadth of 3.0 km. Due to fortuitous observing geometry during some of the radar observations, its rotation state can be determined to great accuracy. The direction of JD6's rotation axis is known more accurately than that of any other asteroid for which only Earth-based observations are available. Chapter 4: One promising way to speed up part of the asteroid shape modeling process is by using Bayesian optimization to test pole directions autonomously. This requires less computational time and less human oversight than a traditional grid search.
Author: National Research Council
Publisher: National Academies Press
ISBN: 0309060834
Category : Science
Languages : en
Pages : 45
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Book Description
Comets and asteroids are in some sense the fossils of the solar system. They have avoided most of the drastic physical processing that shaped the planets and thus represent more closely the properties of the primordial solar nebula. What processing has taken place is itself of interest in decoding the history of our solar neighborhood. Near-Earth objects are also of interest because one or more large ones have been blamed for the rare but devastating events that caused mass extinctions of species on our planet, as attested by recent excitement over the impending passage of asteroid 1997 XF11. The comets and asteroids whose orbits bring them close to Earth are clearly the most accessible to detailed investigation, both from the ground and from spacecraft. When nature kindly delivers the occasional asteroid to the surface of Earth as a meteorite, we can scrutinize it closely in the laboratory; a great deal of information about primordial chemical composition and primitive processes has been gleaned from such objects. This report reviews the current state of research on near-Earth objects and considers future directions. Attention is paid to the important interplay between ground-based investigations and spaceborne observation or sample collection and return. This is particularly timely since one U.S. spacecraft is already on its way to rendezvous with a near-Earth object, and two others plus a Japanese mission are being readied for launch. In addition to scientific issues, the report considers technologies that would enable further advances in capability and points out the possibilities for including near-Earth objects in any future expansion of human exploration beyond low Earth orbit.
Author: National Academies of Sciences, Engineering, and Medicine (U.S.). Committee on Near Earth Object Observations in the Infrared and Visible Wavelengths
Publisher:
ISBN: 9780309493994
Category : Asteroids
Languages : en
Pages : 61
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Book Description
"Near Earth objects (NEOs) have the potential to cause significant damage on Earth. In December 2018, an asteroid exploded in the upper atmosphere over the Bering Sea (western Pacific Ocean) with the explosive force of nearly 10 times that of the Hiroshima bomb. While the frequency of NEO impacts rises in inverse proportion to their sizes, it is still critical to monitor NEO activity in order to prepare defenses for these rare but dangerous threats. Currently, NASA funds a network of ground-based telescopes and a single, soon-to-expire space-based asset to detect and track large asteroids that could cause major damage if they struck Earth. This asset is crucial to NEO tracking as thermal-infrared detection and tracking of asteroids can only be accomplished on a space-based platform. Finding Hazardous Asteroids Using Infrared and Visible Wavelength Telescopes explores the advantages and disadvantages of infrared (IR) technology and visible wavelength observations of NEOs. This report reviews the techniques that could be used to obtain NEO sizes from an infrared spectrum and delineate the associated errors in determining the size. It also evaluates the strengths and weaknesses of these techniques and recommends the most valid techniques that give reproducible results with quantifiable errors"--Publisher's description
Author: Jose M. Diego
Publisher: Springer Science & Business Media
ISBN: 3642112501
Category : Science
Languages : en
Pages : 466
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Book Description
Astronomy is a scienti?c discipline that has developed a rapid and impressive growth in Spain. Thirty years ago, Spain occupied a purely anecdotal presence in the international context, but today it occupies the eighth position in the world in publication of astronomical articles, and, among other successes, owns and op- ates ninety per cent of the world’s largest optical telescope GTC (Gran Telescopio Canarias). The Eighth Scienti?c Meeting of the Spanish Astronomical Society (Sociedad Espanol ̃ a de Astronom ́ a, SEA), held in Santander in July 7–11 2008, whose p- ceedings are in your hands, clearly shows the enthusiasm, motivation and quality of the present Spanish astronomical community. The event brought together 322 participants, who represent almost 50% of Spanish professional astronomers. This percentage, together with the continuously increasing, with respect to previous SEA meetings, number of oral presentations and poster contributions (179 and 127 respectively), con?rms that the SEA conferences have become a point of reference to assess the interests and achievements of astrophysical research in Spain. The most important and current topics of modern Astrophysics were taken into accountat thepreliminarymeeting,aswell as the numberandqualityofparticipants and their contributions, to select the invited speakers and oral contributors. We took a week to enjoy the high quality contributions submitted by Spanish astronomers to the Scienti?c Organizing Committee. The selection was dif?cult. We wish to acknowledge the gentle advice and commitment of the SOC members.
