Detection of sporadic impact flashes on the Moon: Implications for the luminous efficiency of hypervelocity impacts and derived terrestrial impact rates

Icarus ◽  
2006 ◽  
Vol 184 (2) ◽  
pp. 319-326 ◽  
Author(s):  
J ORTIZ ◽  
F ACEITUNO ◽  
J QUESADA ◽  
J ACEITUNO ◽  
M FERNANDEZ ◽  
...  
Keyword(s):  
Luminous Efficiency ◽  
The Moon ◽  
Hypervelocity Impacts

Luminous Efficiency in Hypervelocity Impacts from the 1999 Lunar Leonids

2000 ◽  
Vol 542 (1) ◽  
pp. L65-L68 ◽  
Author(s):  
L. R. Bellot Rubio ◽  
J. L. Ortiz ◽  
P. V. Sada
Keyword(s):  
Luminous Efficiency ◽  
Hypervelocity Impacts

scholarly journals NELIOTA: Methods, statistics, and results for meteoroids impacting the Moon

2020 ◽  
Vol 633 ◽  
pp. A112 ◽  
Author(s):  
A. Liakos ◽  
A. Z. Bonanos ◽  
E. M. Xilouris ◽  
D. Koschny ◽  
I. Bellas-Velidis ◽  
...  
Keyword(s):  
Empirical Relation ◽  
Black Body ◽  
Luminous Efficiency ◽  
Physical Parameters ◽  
The Moon ◽  
Energy Impact ◽  
Lunar Impact ◽  
The Masses ◽  
The Impact ◽  
Near Earth Objects

Context. This paper contains results from the first 30 months of the NELIOTA project for near-Earth objects and meteoroids impacting the lunar surface. We present our analysis of the statistics concerning the efficiency of the campaign and the parameters of the projectiles and those of their impacts. Aims. The parameters of the lunar impact flashes are based on simultaneous observations in two wavelength bands. They are used to estimate the distributions of the masses, sizes, and frequency of the impactors. These statistics can have applications in both space engineering and science. Methods. The photometric fluxes of the flashes are measured using aperture photometry and their apparent magnitudes are calculated using standard stars. Assuming that the flashes follow a black body law of irradiation, the temperatures can be derived analytically, while the parameters of the projectiles are estimated using fair assumptions on their velocity and luminous efficiency of the impacts. Results. There have been 79 lunar impact flashes observed with the 1.2 m Kryoneri telescope in Greece. The masses of the meteoroids range between 0.7 g and 8 kg, and their respective sizes between 1 and 20 cm, depending on their assumed density, impact velocity, and luminous efficiency. We find a strong correlation between the observed magnitudes of the flashes and the masses of the meteoroids. Moreover, an empirical relation between the emitted energies of each band has been derived, allowing for an estimation of the physical parameters of the meteoroids that produce low energy impact flashes. Conclusions. The NELIOTA project has so far the highest detection rate and the faintest limiting magnitude for lunar impacts compared to other ongoing programs. Based on the impact frequency distribution on the Moon, we estimate that sporadic meteoroids with typical masses less than 100 g and sizes less than 5 cm enter the mesosphere of the Earth with a rate of ~108 meteoroids h−1 and also impact Moon with a rate of ~8 meteoroids h−1.

scholarly journals On the Growth of the Earth-Moon System

1974 ◽  
Vol 3 ◽  
pp. 469-473
Author(s):  
F. L. Whipple
Keyword(s):  
Solar Nebula ◽  
Low Density ◽  
Differentiation Process ◽  
The Moon ◽  
Moon System ◽  
Hypervelocity Impacts ◽  
The Earth ◽  
Refractory Minerals ◽  
Gravitational Capture ◽  
Two Bodies

This paper elaborates the postulate that the Earth and Moon became a binary system during their accretional development and that the Moon’s growth was essentially completed before the assumed solar nebula dissipated. The solar nebula was still hot enough at the formation of the two bodies that both consisted largely of the refractory and relatively low-density minerals now characteristic of the Moon. During the subsequent condensation, agglomeration and accretion of siderophile and more volatile higher density minerals, the Earth grew very much faster than the Moon because of (a) its much greater gravitational capture area coupled with retention by a sizeable atmosphere and (t>) the Moon’s velocity, with respect to the solar nebula, which produced a wind that aerodynamically blew away volatiles and smaller debris resulting from hypervelocity impacts of larger planetesimals. This ‘impact differentiation’ process favored the retention of the refractory minerals on the Moon (Figure 1). The Moon’s surprisingly high moment of inertia follows naturally from the basic postulate.

scholarly journals Survival of fossils under extreme shocks induced by hypervelocity impacts

2014 ◽  
Vol 372 (2023) ◽  
pp. 20130190 ◽  
Author(s):  
M. J. Burchell ◽  
K. H. McDermott ◽  
M. C. Price ◽  
L. J. Yolland
Keyword(s):  
Peak Pressure ◽  
Fragment Size ◽  
Hypervelocity Impact ◽  
The Moon ◽  
Hypervelocity Impacts ◽  
The Earth ◽  
Giant Impacts ◽  
The Mean ◽  
Peak Pressures ◽  
Impact Experiments

Experimental data are shown for survival of fossilized diatoms undergoing shocks in the GPa range. The results were obtained from hypervelocity impact experiments which fired fossilized diatoms frozen in ice into water targets. After the shots, the material recovered from the target water was inspected for diatom fossils. Nine shots were carried out, at speeds from 0.388 to 5.34 km s −1 , corresponding to mean peak pressures of 0.2–19 GPa. In all cases, fragmented fossilized diatoms were recovered, but both the mean and the maximum fragment size decreased with increasing impact speed and hence peak pressure. Examples of intact diatoms were found after the impacts, even in some of the higher speed shots, but their frequency and size decreased significantly at the higher speeds. This is the first demonstration that fossils can survive and be transferred from projectile to target in hypervelocity impacts, implying that it is possible that, as suggested by other authors, terrestrial rocks ejected from the Earth by giant impacts from space, and which then strike the Moon, may successfully transfer terrestrial fossils to the Moon.

The motion of a lunar orbiter

1966 ◽  
Vol 25 ◽  
pp. 373
Author(s):  
Y. Kozai
Keyword(s):  
Degrees Of Freedom ◽  
Dimensional Space ◽  
Artificial Satellite ◽  
Equations Of Motion ◽  
Triaxial Ellipsoid ◽  
The Moon ◽  
Secular Motion ◽  
The Earth ◽  
Close Satellite ◽  
The Mean

The motion of an artificial satellite around the Moon is much more complicated than that around the Earth, since the shape of the Moon is a triaxial ellipsoid and the effect of the Earth on the motion is very important even for a very close satellite.The differential equations of motion of the satellite are written in canonical form of three degrees of freedom with time depending Hamiltonian. By eliminating short-periodic terms depending on the mean longitude of the satellite and by assuming that the Earth is moving on the lunar equator, however, the equations are reduced to those of two degrees of freedom with an energy integral.Since the mean motion of the Earth around the Moon is more rapid than the secular motion of the argument of pericentre of the satellite by a factor of one order, the terms depending on the longitude of the Earth can be eliminated, and the degree of freedom is reduced to one.Then the motion can be discussed by drawing equi-energy curves in two-dimensional space. According to these figures satellites with high inclination have large possibilities of falling down to the lunar surface even if the initial eccentricities are very small.The principal properties of the motion are not changed even if plausible values ofJ3andJ4of the Moon are included.This paper has been published in Publ. astr. Soc.Japan15, 301, 1963.

Laboratory Simulation of Lunar Luminescence

1962 ◽  
Vol 14 ◽  
pp. 441-444 ◽  
Author(s):  
J. E. Geake ◽  
H. Lipson ◽  
M. D. Lumb
Keyword(s):  
Science And Technology ◽  
Laboratory Simulation ◽  
The Moon ◽  
Physics Department ◽  
Luminescent Spectrum

Work has recently begun in the Physics Department of the Manchester College of Science and Technology on an attempt to simulate lunar luminescence in the laboratory. This programme is running parallel with that of our colleagues in the Manchester University Astronomy Department, who are making observations of the luminescent spectrum of the Moon itself. Our instruments are as yet only partly completed, but we will describe briefly what they are to consist of, in the hope that we may benefit from the comments of others in the same field, and arrange to co-ordinate our work with theirs.

Formation of Lunar Craters and Bright Rays as a Result of Meteorite Impacts

1962 ◽  
Vol 14 ◽  
pp. 415-418
Author(s):  
K. P. Stanyukovich ◽  
V. A. Bronshten
Keyword(s):  
Explosive Charge ◽  
The Moon ◽  
Meteorite Impacts ◽  
The Earth ◽  
Lunar Craters ◽  
The Impact

The phenomena accompanying the impact of large meteorites on the surface of the Moon or of the Earth can be examined on the basis of the theory of explosive phenomena if we assume that, instead of an exploding meteorite moving inside the rock, we have an explosive charge (equivalent in energy), situated at a certain distance under the surface.

The Origin of the Moon

1962 ◽  
Vol 14 ◽  
pp. 149-155 ◽  
Author(s):  
E. L. Ruskol
Keyword(s):  
Chemical Composition ◽  
Solar System ◽  
The Moon ◽  
The Earth ◽  
The Difference ◽  
Origin Of The Moon

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.

The Origin of the Moon and its Relationship to the Origin of the Solar System

1962 ◽  
Vol 14 ◽  
pp. 133-148 ◽  
Author(s):  
Harold C. Urey
Keyword(s):  
Solar System ◽  
The Moon ◽  
The Past ◽  
The Earth ◽  
Short Period ◽  
Origin Of The Moon

During the last 10 years, the writer has presented evidence indicating that the Moon was captured by the Earth and that the large collisions with its surface occurred within a surprisingly short period of time. These observations have been a continuous preoccupation during the past years and some explanation that seemed physically possible and reasonably probable has been sought.

A Photographic Map of the Moon

1962 ◽  
Vol 14 ◽  
pp. 113-115
Author(s):  
D. W. G. Arthur ◽  
E. A. Whitaker
Keyword(s):  
Lunar Surface ◽  
The Moon ◽  
Map Projection

The cartography of the lunar surface can be split into two operations which can be carried on quite independently. The first, which is also the most laborious, is the interpretation of the lunar photographs into the symbolism of the map, with the addition of fine details from telescopic sketches. An example of this kind of work is contained in Johann Krieger'sMond Atlaswhich consists of photographic enlargements in which Krieger has sharpened up the detail to accord with his telescopic impressions. Krieger did not go on either to convert the photographic picture into the line symbolism of a map, or to place this picture on any definite map projection.

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