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1. The Golden Meteorite Fall: Fireball Trajectory, Orbit and Meteorite Characterization

Author

Brown, P. G., McCausland, P. J. A., Hildebrand, A. R, Hanton, L. T. J., Eckart, L. M., Busemann, H., Krietsch, D., Maden, C., Welten, K., Caffee, M. W., Laubenstein, M., Vida, D., Ciceri, F., Silber, E., Herd, C. D. K., Hill, P., Devillepoix, H., Sansom, Eleanor K., Cupák, Martin, Anderson, Seamus, Flemming, R. L., Nelson, A. J., Mazur, M., Moser, D. E., Cooke, W. J., Hladiuk, D., Malečić, Barbara, Prtenjak, Maja Telišman, and Nowell, R.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Physics - Geophysics
Abstract

The Golden (British Columbia, Canada) meteorite fall occurred on Oct 4, 2021 at 0534 UT with the first recovered fragment (1.3 kg) landing on an occupied bed. The meteorite is an unbrecciated, low-shock (S2) ordinary chondrite of intermediate composition, typed as an L/LL5. From noble gas measurements the cosmic ray exposure age is 25 Ma while gas retention ages are all >2 Ga. Short-lived radionuclides and noble gas measurements of the pre-atmospheric size overlap with estimates from infrasound and lightcurve modelling producing a preferred pre-atmospheric mass of 70-200 kg. The orbit of Golden has a high inclination (23.5 degs) and is consistent with delivery from the inner main belt. The highest probability (60%) of an origin is from the Hungaria group. We propose that Golden may originate among the background S-type asteroids found interspersed in the Hungaria region. The current collection of 18 L and LL chondrite orbits shows a strong preference for origins in the inner main belt, suggesting multiple parent bodies may be required to explain the diversity in CRE ages and shock states., Comment: 92 Pages, 20 Tables, 21 Figures, plus 3 appendices, accepted in Meteoritics and Planetary Science Oct 26 2023

Published
2023

2. The Hamburg Meteorite Fall: Fireball trajectory, orbit and dynamics

Author

Brown, P. G., Vida, D., Moser, D. E., Granvik, M., Koshak, W. J., Chu, D., Steckloff, J., Licata, A., Hariri, S., Mason, J., Mazur, M., Cooke, W., and Krzeminski, Z.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

The Hamburg (H4) meteorite fell on January 17, 2018 at 01:08 UT approximately 10km North of Ann Arbor, Michigan. More than two dozen fragments totaling under one kilogram were recovered, primarily from frozen lake surfaces. The fireball initial velocity was 15.83 $\pm$ 0.05 km/s, based on four independent records showing the fireball above 50 km altitude. The radiant had a zenith angle of 66.1 $\pm$ 0.29 degs and an azimuth of 121.56 $\pm$ 1.2 degs. The resulting low inclination ($<$ 1 deg) Apollo-type orbit has a large aphelion distance and Tisserand value relative to Jupiter (Tj) of $\sim$ 3. Two major flares dominant the energy deposition profile, centred at 24.1 and 21.7 km altitude respectively under dynamic pressures of 5-7 MPa. Our preferred total energy for the Hamburg fireball is 2 to 7 T TNT (8.4 to 28 x 10$^9$ J), which corresponds to a likely initial mass in the range of 60 to 225 kg or diameter between 0.3 to 0.5 m. Based on the model of Granvik et al (2018), the meteorite originated in an escape route from the mid-outer asteroid belt. Hamburg is the 14th known H-chondrite with an instrumentally-derived pre-atmospheric orbit, half of which have small ($<$5 deg) inclinations making connection with (6) Hebe problematic. A definitive parent body consistent with all 14 known H-chondrite orbits remains elusive, Comment: 85 pages, 4 tables, 15 figures, 1 appendix. Accepted to Meteoritics and Planetary Science, June 19, 2019

Published
2019
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3. Music in the Sky Like Bombers: Representations of Airplanes in Interwar Futurist Music

Author

Cooke, W. E. and Cooke, W. E.

Abstract

Since its founding in 1909 by F. T. Marinetti, the artistic movement of futurism gathered momentum as a politically charged avant-garde that challenged tradition and day-to-day life while promoting nationalism, war, and complete artistic expression. Marinetti and his artistic movement followed fascisms’ slow march to power through multiple aesthetic phases, beginning with the study of movement through plastic dynamism (1909-1919), engaging with speed and controlled power through machine aesthetics (1920-1929), cumulating with the more mystical aeroaesthetics (1929-1944), which Marinetti described as “the daughter of fascist aviation and Italian Futurism.” This posturing was not done merely in support of fascism. In 1929, Marinetti was elected to the Academy of Italy, serving within Mussolini’s government. It was then that he published the Futurist Manifesto of Aeropainting and relabeled his own free-words poetry as aeropoesia. In seeking to establish futurism as a national art, Marinetti recognized that his movement must give up the political provocation that so defined it; but in order to preserve the avant-garde identity of futurism, he had to resist Mussolini’s reactionary preferences for realist art. With the conflicting fascist and avant-garde impulses as a guide, this thesis diagnoses aeromusic with a split personality. I contend that the representation of airplanes in aeromusic like that of Mario Monachesi’s, functions as a floating signifier of Italian supremacy under fascism, making it useful fascist propaganda; while the compositional practices of geometricism and synthesis subtly pushed back against conservative tastes in hopes of restoring the avant-garde Italian culture that futurism enjoyed in its first two decades. Aerofuturism, an institutionalized futurism in the 1930s, was a far more postured polemic than the anarcho-fasci-syndicalist futurism of the 1910s: a slap on the wrist of fascist taste. My research explores the music created by the most pro

Published
2024

5. Noise Stabilized Random Attractor

Author

Finn, J. M., Tracy, E. R., Cooke, W. E., and Richardson, A. S.

Subjects
Nonlinear Sciences - Chaotic Dynamics
Abstract

A two dimensional flow model is introduced with deterministic behavior consisting of bursts which become successively larger, with longer interburst time intervals between them. The system is symmetric in one variable x and there are bursts on either side of x = 0, separated by the presence of an invariant manifold at x = 0. In the presence of arbitrarily small additive noise in the x direction, the successive bursts have bounded amplitudes and interburst intervals. This system with noise is proposed as a model for edge localized modes in tokamaks. Further, the bursts can switch from positive to negative x and vice-versa. The probability distribution of burst heights and interburst periods is studied, as is the dependence of the statistics on the noise variance. The modification of this behavior as the symmetry in x is broken is studied, showing qualitatively similar behavior if the symmetry breaking is small enough. Experimental observations of a nonlinear circuit governed by the same equations are presented, showing good agreement., Comment: 46 pages, 18 figures

Published
2005
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6. Mathematics of crimping

Author

Cooke, W.

Subjects
670, Mechanics of deformable solids, Partial differential equations, Numerical analysis
Abstract

The aim of this thesis is to investigate the mathematics and modelling of the industrial crimper, perhaps one of the least well understood processes that occurs in the manufacture of artificial fibre. We begin by modelling the process by which the fibre is deformed as it is forced into the industrial crimper. This we investigate by presuming the fibre to behave as an ideal elastica confined in a two dimensional channel. We consider how the arrangement of the fibre changes as more fibre is introduced, and the forces that are required to confine it. Later, we apply the same methods to a fibre confined to a three dimensional channel. After the fibre has under gone a preliminary deformation, a second process known as secondary crimp can occur. This involves the `zig-zagged' material folding over. We model this process in two ways. First as a series of rigid rods joined by elastic hinges, and then as an elastic with a highly oscillatory natural configuration compressed by thrusts at each end. We observe that both models can be expressed in a very similar manner, and both predict that a buckle can occur from a nearly straight initial condition to an arched formation. We also compare the results to experiments performed on the crimped fibre. Throughout much of the process, the configuration of the fibre does not alter. This part of the process we call the block, and model the material in this region in two ways: as a series of springs; and as an isotropic elastic material. We discuss the coupling between the different regions and the process that occurs in the block, and consider both the steady state and stability of the system.

Published
2000

8. Kinetic Damage from Meteorites

Author

Cooke, W, Brown, P, and Matney, M

Subjects
Lunar And Planetary Science And Exploration
Abstract

Ballistic (kinetic energy) damage from falling meteorites has been recorded in two cases: the 1954 Sylacuga, Alabama meteorite of 4 kilogram mass which indirectly hit Ann Hodges and the 1992 Mbale meteorite fall where a 4 gram-sized meteorite struck a young boy. Neither event was fatal. Structures damaged by meteorites are much more common and include mail boxes (Figure 1) and cars (Figure2). Figure 3 shows that meteorite fragments of order 0.1 kilograms may cause serious human injury/fatality. Halliday et al (1985) estimated a human is struck once per decade by a meteorite (most likely gram-sized) while more than a dozen structures should be impacted annually by meteorite fragments.

Published
2019

9. Recent Corrections to Meteoroid Environment Models

Author

Moorhead, A. V, Brown, P. G, Campbell-Brown, M. D, Moser, D. E, Blaauw, R. C, and Cooke, W. J

Subjects
Lunar And Planetary Science And Exploration
Abstract

The dynamical and physical characteristics of a meteoroid affects its behavior in the atmosphere and the damage it does to spacecraft surfaces. Accurate environment models must therefore correctly describe the speed, size, density, and direction of meteoroids. However, the measurement of dynamical characteristics such as speed is subject to observational biases, and physical properties such as size and density cannot be directly measured. De-biasing techniques and proxies are needed to overcome these challenges. In this presentation, we discuss several recent improvements to the derivation of the meteoroid velocity, directionality, and bulk density distributions. We derive our speed distribution from observations made by the Canadian Meteor Orbit Radar. These observations are de-biased using modern descriptions of the ionization efficiency and sharpened to remove the effects of measurement uncertainty, and the result is a meteoroid speed distribution that is skewed slower than in previous analyses. We also adopt a higher fidelity density distribution than that used by many older models. In our distribution, meteoroids with T(sub J) less than 2 are assigned to a low-density population, while those with T(sub J) greater than 2 have higher densities. This division and the distributions themselves are derived from the densities reported by Kikwaya et al. (2009, 2011). These changes have implications for the environment. For instance, helion and antihelion meteors have lower speeds and higher densities than apex and toroidal meteors. A slower speed distribution therefore corresponds to a sporadic environment that is more completely dominated by the helion and antihelion sources than in previous models. Finally, assigning these meteors high densities further increases their significance from a spacecraft damage perspective.

Published
2017

12. Kinetic Damage from Meteorites

Author

Cooke, W, Brown, P, and Matney, M

Subjects
Solar Physics
Abstract

Comparing the natural meteorite flux at the Earth's surface to that of space debris, re-entering debris is ~2 orders of magnitude less of a kinetic hazard at all but the very largest (and therefore rarest) sizes compared to natural impactors. Debris re-entries over several metric tonnes are roughly as frequent as natural impactors, but the survival fraction is expected to be much higher. Kinetic hazards from meteorites are very small, with only one recorded (indirect) injury reported. We expect fatalities to be even more rare, on the order of one person killed per several millennia. That several reports exist of small fragments/sand hitting people during meteorite falls is consistent with our prediction that this should occur every decade or so.

Published
2017

13. A Comparison of Results From NASA's Meteoroid Engineering Model to the LDEF Cratering Record

Author

Ehlert, S, Moorhead, A, and Cooke, W. J

Subjects
Lunar And Planetary Science And Exploration
Abstract

NASA's Long Duration Exposure Facility (LDEF) has provided an extensive record of the meteoroid environment in Low Earth Orbit. LDEF's combination of fixed orientation, large collecting area, and long lifetime imposes constraints on the absolute flux of potentially hazardous meteoroids. The relative impact rate on each of LDEF's fourteen surfaces arises from the underlying velocity distribution and directionality of the meteoroid environment. For the first time, we model the meteoroid environment encountered by LDEF over its operational lifetime using NASA's Meteoroid Engineering Model Release 2 (MEMR2) and compare the model results with the observed craters of potentially hazardous meteoroids (i.e. crater diameters larger than approximately 0.6 mm). We discuss the extent to which the observations and model agree and how the impact rates across all of the LDEF surfaces may suggest improvements to the underlying assumptions that go into future versions of MEM.

Published
2017

14. The Velocity and Density Distribution of Earth-Intersecting Meteoroids: Implications for Environment Models

Author

Moorhead, A. V, Brown, P. G, Campbell-Brown, M. D, Moser, D. E, Blaauw, R. C, and Cooke, W. J

Subjects
Space Transportation And Safety
Abstract

Meteoroids are known to damage spacecraft: they can crater or puncture components, disturb a spacecraft's attitude, and potentially create secondary electrical effects. Because the damage done depends on the speed, size, density, and direction of the impactor, accurate environment models are critical for mitigating meteoroid-related risks. Yet because meteoroid properties are derived from indirect observations such as meteors and impact craters, many characteristics of the meteoroid environment are uncertain. In this work, we present recent improvements to the meteoroid speed and density distributions. Our speed distribution is derived from observations made by the Canadian Meteor Orbit Radar. These observations are de-biased using modern descriptions of the ionization efficiency. Our approach yields a slower meteoroid population than previous analyses (see Fig. 1 for an example) and we compute the uncertainties associated with our derived distribution. We adopt a higher fidelity density distribution than that used by many older models. In our distribution, meteoroids with TJ less than 2 are assigned to a low-density population, while those with TJ greater than 2 have higher densities (see Fig. 2). This division and the distributions themselves are derived from the densities reported by Kikwaya et al. These changes have implications for the environment: for instance, the helion/antihelion sporadic sources have lower speeds than the apex and toroidal sources and originate from high-T(sub J) parent bodies. Our on-average slower and denser distributions thus imply that the helion and antihelion sources dominate the meteoroid environment even more completely than previously thought. Finally, for a given near-Earth meteoroid cratering rate, a slower meteoroid population produces a comparatively higher rate of satellite attitude disturbances.

Published
2017

15. Simultaneous Optical and Meteor Head Echo Measurements Using the Middle Atmosphere Alomar Radar System (MAARSY)

Author

Cooke, W. J, Brown, P. G, Stober, G, Schult, C, Krzeminski, Z, and Chau, J. L

Subjects
Instrumentation And Photography
Abstract

We describe a two year campaign of simultaneous automated meteor optical and head echo radar measurements conducted with the Middle Atmosphere Alomar Radar System (MAARSY). This campaign was established with the following goals: Compare trajectories as measured by MAARSY and the two optical stations for a range of meteoroid masses. Compare photometric and dynamic mass measured optically with radar-derived masses (inter-calibration of mass scales). Use the best observed simultaneous events to fuse all metric, photometric and ionization estimates together and apply different ablation models to self-consistently model these highest quality events.

Published
2017

17. Curved strata and sandpit in Headen Hill, I. W. Drawn by T. Webster. Engraved by W. B. Cooke. London: Published by Payne and Foss. 1815. (to accompany) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, and Cooke, W. B.

Subjects
England, Isle of Wight (England)
Abstract

Engraved view of sandpit in Headen Hill in Isle of Wight, England., First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1815

18. Compton Bay, I. W. Drawn by T. Webster. Engraved by W. B. Cooke. London: Published by Payne and Foss. 1815. (to accompany) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, and Cooke, W. B.

Subjects
England, Isle of Wight (England)
Abstract

Engraved view of Compton Bay on the southwest section of the Isle of Wight, England., First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1815

19. Handfast point in Dorsetshire. Drawn by T. Webster. Engraved by W. B. Cooke. London: Published by Payne and Foss. 1815. (to accompany) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, and Cooke, W. B.

Subjects
England, Dorsetshire (England), Isle of Wight (England)
Abstract

Engraved folded view of Handfast point in Dorset., First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1815

20. Culver Cliff, I. W. Drawn by T. Webster. Engraved by W. B. Cooke. London: Published by Payne and Foss. 1815. (to accompany) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, and Cooke, W. B.

Subjects
England, Isle of Wight (England)
Abstract

Engraved folded view of Culver Cliff, Isle of Wight, England., First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1815

21. Chalk Pit on Branding Down, I. W. Drawn by T. Webster. Engraved by W. Cooke. London: Published by Payne and Foss. 1815. (to accompany) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, and Cooke, W. B.

Subjects
England, Isle of Wight (England)
Abstract

Engraved view of Brading Down at the eastern end of the Isle of Wight, central chalk ridge., First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1815

22. Vertical and curved strata, White Cliff Bay, Isle of Wight. Drawn by T. Webster. Engraved by W. B. Cooke. London: Published by Payne and Foss. 1815. (to accompany) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, and Cooke, W. B.

Subjects
England, Isle of Wight (England)
Abstract

Engraved view of north side of the Whitecliff Bay in the easternmost point of the Isle of Wight, England., First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1815

23. Yaverland Church, I. W. Drawn by Sir Henry C. Englefield, Bart. Engraved by W. B. Cooke. London: Published by Payne and Foss. 1815. (to accompany) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, and Cooke, W. B.

Subjects
England, Isle of Wight (England)
Abstract

Engraved view of Yaverland Chuch on the Isle of Wight, England., First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1815

24. Black - Gang Chine, I. W. Drawn by Sir Henry C. Englefield, Bart. Engraved by W. B. Cooke. London: Published by Payne and Foss. 1815. (to accompany) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, and Cooke, W. B.

Subjects
England, Isle of Wight (England)
Abstract

Engraved view of Blackgang Chine at the southern tip of the Isle of Wight, England., First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1815

25. Chalk Cliffs.,White Cliff Bay, I. W. Drawn by Sir Henry C. Englefield, Bart. Engraved by W. B. Cooke. London: Published by Payne and Foss. 1815. (to accompany) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, and Cooke, W. B.

Subjects
England, Isle of Wight (England)
Abstract

Engraved view of the Chalk Cliffs, Whitecliff Bay of Isle of the Wight, England., First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1815

26. Freshwater Cave, I. W. Drawn by Sir Henry C. Englefield, Bart. Engraved by W. B. Cooke. London: Published by Payne and Foss. 1815. (to accompany) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, and Cooke, W. B.

Subjects
England, Isle of Wight (England)
Abstract

Engraved view of Freshwater Cave at the western end of the Isle of Wight, England., First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1815

27. Clay Cliffs. White Cliff Bay, I. W. Drawn by Sir Henry C. Englefield, Bart. Engraved by W. B. Cooke. London: Published by Payne and Foss. 1815. (to accompany) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, and Cooke, W. B.

Subjects
England, Isle of Wight (England)
Abstract

Engraved view of white and vertical Clay Cliffs, Whitecliff Bay, east of the Isle Wight, England., First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1815

28. Dunnose Cliff, I. W. Drawn by Sir Henry C. Englefield, Bart. Engraved by W. B. Cooke. London: Published by Payne and Foss. 1815. (to accompany) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, and Cooke, W. B.

Subjects
England, Isle of Wight (England)
Abstract

Engraved view of Dunnose on the south eastern coast of the Isle of Wight, England., First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1815

29. (Index Page to) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight. By Sir Henry C. Englefield, Bart ... London: Printed by William Plumber and Co., for Payne and Foss … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, Cooke, W., and Cooke, G.

Abstract

Index. London: Printed by W. Bulmer and Co., First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1816

30. (Title Page to) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight. By Sir Henry C. Englefield, Bart. With additional observations on the strata of the island and their continuation in the adjacent parts of Dorsetshire by Thomas Webster. Illustrated by maps and numerous engravings by W. and G. Cooke from original drawings by Sir H. Englefield and T. Webster. London: Printed by William Plumber and Co., for Payne and Foss … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, Cooke, W., and Cooke, G.

Abstract

First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1816

31. (Composite Text to) Description of the Isle of Wight. (to accompany) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight. By Sir Henry C. Englefield, Bart ... London: Printed by William Plumber and Co., for Payne and Foss … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, Cooke, W., and Cooke, G.

Abstract

Includes title: Page 1., First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1816

32. (Covers to) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight. By Sir Henry C. Englefield, Bart. With additional observations on the strata of the island and their continuation in the adjacent parts of Dorsetshire by Thomas Webster. Illustrated by maps and numerous engravings by W. and G. Cooke from original drawings by Sir H. Englefield and T. Webster. London: Printed by William Plumber and Co., for Payne and Foss … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, Cooke, W., and Cooke, G.

Abstract

Covers to Englefield Isle of Wight., First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1816

33. (Text Page to) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight. By Sir Henry C. Englefield, Bart. With additional observations on the strata of the island and their continuation in the adjacent parts of Dorsetshire by Thomas Webster. Illustrated by maps and numerous engravings by W. and G. Cooke from original drawings by Sir H. Englefield and T. Webster. London: Printed by William Plumber and Co., for Payne and Foss … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, Cooke, W., and Cooke, G.

Abstract

Dedication text., First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1815

34. (Half Title Page to) A description of principal picturesque beauties, antiquities and geological phoenomena of the isle of Wight. By Sir Henry C. Englefield, Bart. With additional observations on the strata of the island and their continuation in the adjacent parts of Dorsetshire by Thomas Webster. Illustrated by maps and numerous engravings by W. and G. Cooke from original drawings by Sir H. Englefield and T. Webster. London: Printed by William Plumber and Co., for Payne and Foss … 1816.

Author

Englefield, Henry Charles, Sir Bart., 1752-1822, Webster, Thomas, Cooke, W., and Cooke, G.

Abstract

First and only edition of the most important published work of Sir Henry Englefield, antiquary and writer on science, with additional observations on the strata of the Island, and their continuation in the adjacent parts of Dorsetshire. By Thomas Webster. The work concerned as much with historic architecture and picturesque landscape as with geology. It consists of 47 engraved plates, 9 of them folding, one hand colored, and 3 folding maps, one hand-colored, including 1 plan and 1 cross section. Views and maps engraved by W. and G. Cooke and J. Walker, from Original Drawings by Sir H. Englefield and T. Webster. Half-title bound in. Includes xxvii pages of preface and explanation of the plates, 238 pages of descriptive text, 4 pages of index. Bound in dark reddish-brown half morocco covers with title “Englefield Isle of Wight” in gilt in on spine.

Published
1816

35. In sickness and in health: the functional role of EVs in physiology and pathology in vivo Part II: Pathology

Author

Yates, AG, Pink, RC, Erdbruegger, U, Siljander, PR-M, Dellar, ER, Pantazi, P, Akbar, N, Cooke, W, Vatish, M, Dias-Neto, E, Anthony, DC, and Couch, Y

Abstract

It is clear from Part I of this series that extracellular vesicles (EVs) play a critical role in maintaining the homeostasis of most, if not all, normal physiological systems. However, the majority of our knowledge about EV signalling has come from studying them in disease. Indeed, EVs have consistently been associated with propagating disease pathophysiology. The analysis of EVs in biofluids, obtained in the clinic, has been an essential of the work to improve our understanding of their role in disease. However, to interfere with EV signalling for therapeutic gain, a more fundamental understanding of the mechanisms by which they contribute to pathogenic processes is required. Only by discovering how the EV populations in different biofluids change—size, number, and physicochemical composition—in clinical samples, may we then begin to unravel their functional roles in translational models in vitro and in vivo, which can then feedback to the clinic. In Part II of this review series, the functional role of EVs in pathology and disease will be discussed, with a focus on in vivo evidence and their potential to be used as both biomarkers and points of therapeutic intervention.

Published
2021

36. A Study of the Number of Black Graduate Student Applications for Fall, 1970.

Author

Cornell Univ., Ithaca, NY. Graduate School. and Cooke, W. D.

Abstract

This report presents some statistical data on black graduate student applicants. Twenty-five major graduate schools were requested to supply information on the number of identifiable black applicants by field; 11 were able to supply the data. They were: Berkeley, Brown, Columbia, Cornell, Harvard, Princeton, Minnesota, MIT, Syracuse, University of Wisconsin, and Yale. Applications varied from 346 to 84. Berkeley had 346 applications, 7 schools had between 100 and 200 applicants, and 3 had under 100. Some university departments attracted disproportionately large percentages of the total number of applicants in a particular field: MIT, for example, received 62% of all city planning applications, and Brown University received 45% of the total number in Romance Studies. The humanities and social sciences attracted 85% of the students, while the physical sciences received fewer than 10% of the applications. The total number of applications to the 11 institutions was 1,694 - a very small percentage of the approximately 50,000 Blacks who received undergraduate degrees in 1969-70. Of 546 applications examined for duplication of applicants, 425 represented actual individuals. (AF)

Published
1970

37. [Recruiting Black Graduate Students.]

Author

Cornell Univ., Ithaca, NY. Graduate School. and Cooke, W. D.

Abstract

There are several barriers to increasing the number of black graduate students in the universities. The first impediment is the loss of overall graduate student support which will be sharply felt beginning in the fall of 1971. The Nixon Administration's program places a heavy emphasis on loans and persons from low income families are often reluctant to add to their debts accumulated from their undergraduate years. Another problem is that a relatively small number of black graduates apply to graduate school; many are siphoned off into industrial and business careers after graduation. A third barrier is the fact that black applicants tend to concentrate in a small number of fields: generally the humanities and social sciences, with almost no applications in the engineering field. Given these factors, the criteria used for admissions must be examined. The validity of the usual predictors varies widely across different areas of study, and motivation may be more important than undergraduate grade point average. (AF)

Published
1970

39. Mercer County Teacher Education Center.

Author

Mercer County Schools, Princeton, WV. and Cooke, W. R.

Abstract

This booklet contains program description and policy guidelines for the Mercer County Teacher Education Center (Princeton, West Virginia), a cooperative center organized and operated by Bluefield State College, Concord College, Mercer County Public Schools, and the W. Va. State Department of Education. Part 1 sketches the history of the Center (founded in July 1969) and lists basic assumptions regarding cooperative responsibility for a comprehensive program of teacher training. Included is an outline of the administrative organization and lists of the duties and responsibilities of the advisory council (composed of representatives of all cooperating organizations), which is responsible for general supervision of the Center. Part 2 sketches program philosophy and describes each component: pre-student teaching modules (experiences in the public schools for college sophomores and juniors), the student teaching program, the inservice education program throughout the county, and the continuing education program for beginning teachers. Part 3 lists functions and responsibilities for all involved: county school system, teacher education institutions, state department of education, center coordinator, student teacher (13 required competencies are listed), cooperating teacher, college-based teacher educator, county supervisor, building principal, and each public school selected as a site for observation and student teaching. (JS)

40. Martian Atmospheric Methane Plumes from Meteor Shower Infall: A Hypothesis

Author

Fries, M, Christou, A, Archer, D, Conrad, P, Cooke, W, Eigenbrode, J, ten Kate, I. L, Matney, M, Niles, P, and Sykes, M

Subjects
Lunar And Planetary Science And Exploration
Abstract

Methane plumes in the martian atmosphere have been detected using Earth-based spectroscopy, the Planetary Fourier Spectrometer on the ESA Mars Express mission, and the NASA Mars Science Laboratory. The methane's origin remains a mystery, with proposed sources including volcanism, exogenous sources like impacts and interplanetary dust, aqueous alteration of olivine in the presence of carbonaceous material, release from ancient deposits of methane clathrates, and/or biological activity. To date, none of these phenomena have been found to reliably correlate with the detection of methane plumes. An additional source exists, however: meteor showers could generate martian methane via UV pyrolysis of carbon-rich infall material. We find a correlation between the dates of Mars/cometary orbit encounters and detections of methane on Mars. We hypothesize that cometary debris falls onto Mars during these interactions, depositing freshly disaggregated meteor shower material in a regional concentration. The material generates methane via UV photolysis, resulting in a localized "plume" of short-lived methane.

Published
2016

41. Spacecraft Risk Posed by the 2016 Perseid Outburst

Author

Cooke, W. J, Moser, D. E, and Moorhead, A. V

Subjects
Astrophysics, Astronomy
Abstract

The Perseids are one of the more prolific annual showers, known for high rates and for producing bright meteors. Outbursts of this shower have been noted in the 1860s, the early 1990s, 2004, and 2009, with the 1993 outburst being especially active (peak ZHR above 300). The 1993 Perseids also affected the space-faring nations, as the launch of the STS-51 mission was delayed by NASA until after the shower maximum due to an inability to predict the shower intensity, and the ESA telecommunications satellite Olympus suffered a mission-ending anomaly attributed to a static discharge caused by a Perseid impact [1]. Rates were again high (peak ZHR around 200) in 2009, when the NASA/USGS imaging satellite Landsat-5 experienced a gyro anomaly just before the shower peak; however in this case, the satellite was recovered and normal operations resumed one week later [2]. It is interesting to note that both spacecraft anomalies were not what is typically expected from meteoroid strikes, i.e., physical damage or an attitude displacement due to transfer of momentum. It would appear that the very fast Perseids (59 km s(sup -1) have a marked ability to produce plasma upon impact, which can then serve as a conductive path for discharge currents. The shower is expected to outburst again in 2016, and we present the results from the MSFC Meteoroid Stream Model [4], which predicts enhanced activity on a level similar to that of 2009 as the Earth passes through several debris trails on the night of August 11-12 (UT). We then compare our results to those of other modelers.

Published
2016

42. Optical and Radar Measurements of the Meteor Speed Distribution

Author

Moorhead, A. V, Brown, P. G, Campbell-Brown, M. D, Kingery, A, and Cooke, W. J

Subjects
Lunar And Planetary Science And Exploration, Communications And Radar
Abstract

The observed meteor speed distribution provides information on the underlying orbital distribution of Earth-intersecting meteoroids. It also affects spacecraft risk assessments; faster meteors do greater damage to spacecraft surfaces. Although radar meteor networks have measured the meteor speed distribution numerous times, the shape of the de-biased speed distribution varies widely from study to study. Optical characterizations of the meteoroid speed distribution are fewer in number, and in some cases the original data is no longer available. Finally, the level of uncertainty in these speed distributions is rarely addressed. In this work, we present the optical meteor speed distribution extracted from the NASA and SOMN allsky networks [1, 2] and from the Canadian Automated Meteor Observatory (CAMO) [3]. We also revisit the radar meteor speed distribution observed by the Canadian Meteor Orbit Radar (CMOR) [4]. Together, these data span the range of meteoroid sizes that can pose a threat to spacecraft. In all cases, we present our bias corrections and incorporate the uncertainty in these corrections into uncertainties in our de-biased speed distribution. Finally, we compare the optical and radar meteor speed distributions and discuss the implications for meteoroid environment models.

Published
2016

43. Determination of the Meteor Limiting Magnitude

Author

Kingery, A, Blaauw, R, and Cooke, W. J

Subjects
Instrumentation And Photography
Abstract

The limiting meteor magnitude of a meteor camera system will depend on the camera hardware and software, sky conditions, and the location of the meteor radiant. Some of these factors are constants for a given meteor camera system, but many change between meteor shower or sporadic source and on both long and short timescales. Since the limiting meteor magnitude ultimately gets used to calculate the limiting meteor mass for a given data set, it is important to have an understanding of these factors and to monitor how they change throughout the night, as a 0.5 magnitude uncertainty in limiting magnitude translates to a uncertainty in limiting mass by a factor of two.

Published
2016

44. Martian Methane From a Cometary Source: A Hypothesis

Author

Fries, M, Christou, A, Archer, D, Conrad, P, Cooke, W, Eigenbrode, J, ten Kate, I. L, Matney, M, Niles, P, Sykes, M, Steele, A, and Treiman, A

Subjects
Lunar And Planetary Science And Exploration
Abstract

In recent years, methane in the martian atmosphere has been detected by Earth-based spectroscopy, the Planetary Fourier Spectrometer on the ESA Mars Express mission, and the NASA Mars Science Laboratory. The methane's origin remains a mystery, with proposed sources including volcanism, exogenous sources like impacts and interplanetary dust, aqueous alteration of olivine in the presence of carbonaceous material, release from ancient deposits of methane clathrates, and/or biological activity. An additional potential source exists: meteor showers from the emission of large comet dust particles could generate martian methane via UV pyrolysis of carbon-rich infall material. We find a correlation between the dates of Mars/cometary orbit encounters and detections of methane on Mars. We hypothesize that cometary debris falls onto Mars during these interactions, generating methane via UV photolysis.

Published
2016

47. The Role of Grades in Gaining Admission to Highly Selective Medical Schools.

Author

Cooke, W. D.

Abstract

A study of over 8,000 admissions of Cornell University (New York) graduates to 19 highly selective medical schools, 1982-89, found that grade point average (GPA) was extremely influential especially at 9 schools. It was concluded that applicants often receive encouragement to continue the application process despite little chance of acceptance. (Author/MSE)

Published
1992

50. A 500-kiloton airburst over Chelyabinsk and an enhanced hazard from small impactors

Author

Brown, P.G., Assink, J.D., Astiz, L., Blaauw, R., Boslough, M.B., Borovicka, J., Brachet, N., Brown, D., Campbell-Brown, M., Ceranna, L., Cooke, W., de Groot-Hedlin, C., Drob, D.P., Edwards, W., Evers, L.G., Garces, M., Gill, J., Hedlin, M., Kingery, A., Laske, G., Le Pichon, A., Mialle, P., Moser, D.E., Saffer, A., Silber, E., Smets, P., Spalding, R.E., Spurny, P., Tagliaferri, E., Uren, D., Weryk, R.J., Whitaker, R., and Krzeminski, Z.

Subjects
Asteroids -- Observations -- Environmental aspects, Environmental impact analysis -- Methods, Environmental issues, Science and technology, Zoology and wildlife conservation
Abstract

Most large (over a kilometre in diameter) near-Earth asteroids are now known, but recognition that airbursts (or fireballs resulting from nuclear-weapon-sized detonations of meteoroids in the atmosphere) have the potential to do greater damage (1) than previously thought has shifted an increasing portion of the residual impact risk (the risk of impact from an unknown object) to smaller objects (2). Above the threshold size of impactor at which the atmosphere absorbs sufficient energy to prevent a ground impact, most of the damage is thought to be caused by the airburst shock wave (3), but owing to lack of observations this is uncertain (4,5). Here we report an analysis of the damage from the airburst of an asteroid about 19 metres (17 to 20 metres) in diameter southeast of Chelyabinsk, Russia, on 15 February 2013, estimated to have an energy equivalent of approximately 500 (± 100) kilotons of trinitrotoluene (TNT, where 1 kiloton of TNT = 4.185 x [10.sup.12] joules). We show that a widely referenced technique (4-6) of estimating airburst damage does not reproduce the observations, and that the mathematical relations (7) based on the effects of nuclear weapons--almost always used with this technique--overestimate blast damage. This suggests that earlier damage estimates (5,6) near the threshold impactor size are too high. We performed a global survey of airbursts of a kiloton or more (including Chelyabinsk), and find that the number of impactors with diameters of tens of metres may be an order of magnitude higher than estimates based on other techniques (8,9). This suggests a non-equilibrium (if the population were in a long-term collisional steady state the size-frequency distribution would either follow a single power law or there must be a size-dependent bias in other surveys) in the near-Earth asteroid population for objects 10 to 50 metres in diameter, and shifts more of the residual impact risk to these sizes., (24,25) (26) (10) The Chelyabinsk airburst (10) was observed globally by multiple instruments--including infrasound, seismic, US government sensors and more than 400 video cameras--at ranges up to 700 km away. [...]

Published
2013

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