Physical Properties of Near-Earth Objects

Asteroids III ◽  
2002 ◽  
pp. 255-272
Author(s):  
Richard P. Binzel ◽  
Dmitrij F. Lupishko ◽  
Mario Di Martino ◽  
Robert J. Whiteley ◽  
Gerhard J. Hahn
Keyword(s):  
Physical Properties ◽  
Near Earth Objects

scholarly journals Near-Earth Objects 400 Years after Galileo: Physical Properties and Internal Structure

2010 ◽  
Vol 6 (S269) ◽  
pp. 234-239
Author(s):  
Dmitrij Lupishko ◽  
Zhanna Pozhalova
Keyword(s):  
Optical Properties ◽  
Physical Properties ◽  
Internal Structure ◽  
Binary Systems ◽  
Near Earth Objects ◽  
Asteroids And Comets

AbstractThe review contains the most recent data on near-Earth objects such as their sizes and densities, rotation and shapes, taxonomy and mineralogy, optical properties and structure of their surfaces, binary systems among the NEOs and internal structure of asteroids and comets constituted the NEO population.

scholarly journals Near-Earth objects as principal impactors of the Earth: Physical properties and sources of origin

2006 ◽  
Vol 2 (S236) ◽  
pp. 251-260
Author(s):  
Dimitrij F. Lupishko ◽  
Mario Di Martino ◽  
Richard P. Binzel
Keyword(s):  
Physical Properties ◽  
Binary Systems ◽  
Raw Materials ◽  
Thermal Inertia ◽  
Point Of View ◽  
Main Belt ◽  
Asteroid Hazard ◽  
Axis Rotation ◽  
Near Earth Objects ◽  
Cometary Origin

AbstractNear-Earth objects (NEOs) are objects of a special interest from the point of view not only of cosmogonic problems of the Solar system, but of the applied problems as well (the problem of asteroid hazard, NEOs as the potential sources of raw materials, etc.). They are much smaller in sizes than main-belt asteroids (MBAs), very irregular in shape and covered with a great number of craters of different sizes. Most of NEOs are covered by regolith of low thermal inertia and different thickness. Objects with complex non-principal axis rotation (tumbling bodies) and with super-fast rotational periods have been detected among them. The new data, based on photometric and radar observations, evidence that about 15-20 %; of NEOs could be binary systems. Most of the classified NEOs fragments of differentiated assemblages of S-and Q-types. Analysis of physical properties of NEOs clearly indicates that the asteroid main-belt is the principal source of their origin and only about 10 % of NEOs have a cometary origin.

A Summary and Update on NASA’s Planetary Defense Program.

2020 ◽  
Author(s):  
Doris Daou ◽  
Lindley Johnson
Keyword(s):  
Early Detection ◽  
Physical Properties ◽  
Entire Population ◽  
Significant Progress ◽  
Ongoing Effort ◽  
Planetary Defense ◽  
The Status ◽  
Government Planning ◽  
Near Earth Objects ◽  
Asteroids And Comets

<p>NASA and its partners maintain a watch for near-Earth objects (NEOs), asteroids and comets that pass within Earth’s vicinity, as part of an ongoing effort to discover, catalog, and characterize these bodies and to determine if any pose an impact threat. NASA’s Planetary Defense Coordination Office (PDCO) is responsible for:</p><ul><li>Ensuring the early detection of potentially hazardous objects (PHOs) – asteroids and comets whose orbits are predicted to bring them within 0.05 astronomical units of Earth's orbit; and of a size large enough to reach Earth’s surface – that is, greater than perhaps 30 to 50 meters;</li> <li>Tracking and characterizing PHOs and issuing warnings about potential impacts;</li> <li>Providing timely and accurate communications about PHOs; and</li> <li>Performing as a lead coordination node in U.S. Government planning for response to an actual impact threat.</li> </ul><p> </p><p>NASA’s current congressionally-mandated objective is to detect, track, and catalogue at least 90 percent of NEOs equal to or greater than 140 meters in size by 2020, and characterize the physical properties of a subset representative of the entire population. This mandate will likely not be met given current resources dedicated to the task; however significant progress is being made.</p><p>In this paper, we will report on the status of our program and the missions working to support our planetary defense coordination office. In addition, we will provide the latest detections and characterizations results. Our office continues to work diligently with our international partners to achieve our goals and continue to safeguard Earth with the latest technologies available.</p>

The Photometric Properties of the Ap Stars

1976 ◽  
Vol 32 ◽  
pp. 365-377 ◽  
Author(s):  
B. Hauck
Keyword(s):  
Physical Properties ◽  
Ap Stars

The Ap stars are numerous - the photometric systems tool It would be very tedious to review in detail all that which is in the literature concerning the photometry of the Ap stars. In my opinion it is necessary to examine the problem of the photometric properties of the Ap stars by considering first of all the possibility of deriving some physical properties for the Ap stars, or of detecting new ones. My talk today is prepared in this spirit. The classification by means of photoelectric photometric systems is at the present time very well established for many systems, such as UBV, uvbyβ, Vilnius, Geneva and DDO systems. Details and methods of classification can be found in Golay (1974) or in the proceedings of the Albany Colloquium edited by Philip and Hayes (1975).

The Infection of Cells by Bullet-Shaped Viruses

1969 ◽  
Vol 27 ◽  
pp. 372-373
Author(s):  
Frederick A. Murphy ◽  
Alyne K. Harrison ◽  
Sylvia G. Whitfield
Keyword(s):  
Electron Microscopy ◽  
Physical Properties ◽  
Host Cell ◽  
Thin Section ◽  
Cultured Cells ◽  
Cell Infection ◽  
Thin Section Electron Microscopy ◽  
Section Electron ◽  
Section Electron Microscopy

The bullet-shaped viruses are currently classified together on the basis of similarities in virion morphology and physical properties. Biologically and ecologically the member viruses are extremely diverse. In searching for further bases for making comparisons of these agents, the nature of host cell infection, both in vivo and in cultured cells, has been explored by thin-section electron microscopy.

Transmission electron microscopy of composite materials

1988 ◽  
Vol 46 ◽  
pp. 1012-1015
Author(s):  
K.P.D. Lagerlof
Keyword(s):  
Composite Materials ◽  
Physical Properties ◽  
Structural Defects ◽  
Structural Composites ◽  
Multiphase Materials ◽  
Structural Reinforcement ◽  
Transmission Electron ◽  
Reinforced Fiber ◽  
Particulate Reinforced Composites ◽  
Definition Of

Although most materials contain more than one phase, and thus are multiphase materials, the definition of composite materials is commonly used to describe those materials containing more than one phase deliberately added to obtain certain desired physical properties. Composite materials are often classified according to their application, i.e. structural composites and electronic composites, but may also be classified according to the type of compounds making up the composite, i.e. metal/ceramic, ceramic/ceramie and metal/semiconductor composites. For structural composites it is also common to refer to the type of structural reinforcement; whisker-reinforced, fiber-reinforced, or particulate reinforced composites [1-4].For all types of composite materials, it is of fundamental importance to understand the relationship between the microstructure and the observed physical properties, and it is therefore vital to properly characterize the microstructure. The interfaces separating the different phases comprising the composite are of particular interest to understand. In structural composites the interface is often the weakest part, where fracture will nucleate, and in electronic composites structural defects at or near the interface will affect the critical electronic properties.

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