Meteor shower radiant dispersions in Global Meteor Network data

2021 ◽  
Vol 508 (1) ◽  
pp. 326-339
Author(s):  
Althea V Moorhead ◽  
Tiffany Clements ◽  
Denis Vida
Keyword(s):  
Meteor Shower ◽  
Common Source ◽  
Network Data ◽  
Meteor Showers ◽  
The Earth ◽  
Over Time

ABSTRACT Meteor showers occur when streams of meteoroids originating from a common source intersect the Earth. There will be small dissimilarities between the direction of motion of different meteoroids within a stream, and these small differences will act to broaden the radiant, or apparent point of origin, of the shower. This dispersion in meteor radiant can be particularly important when considering the effect of the Earth’s gravity on the stream, as it limits the degree of enhancement of the stream’s flux due to gravitational focusing. In this paper, we present measurements of the radiant dispersion of 12 showers using observations from the Global Meteor Network. We find that the median offset of individual meteors from the shower radiant ranges from 0.32○ for the eta Aquariids to 1.41○ for the Southern Taurids. We also find that there is a small but statistically significant drift in Sun-centred ecliptic radiant and/or geocentric speed over time for most showers. Finally, we compare radiant dispersion with shower duration and find that, in contrast with previous results, the two quantities are not correlated in our data.

Geographical aspects of the diffusion of passive houses

2013 ◽  
Vol 4 (2) ◽  
pp. 151-156 ◽  
Author(s):  
G. Kozma ◽  
E. Molnár ◽  
K. Czimre ◽  
J. Pénzes
Keyword(s):  
Energy Consumption ◽  
Energy Resources ◽  
Substantial Part ◽  
Renewable Energy Resources ◽  
Passive House ◽  
The Earth ◽  
Passive Houses ◽  
The Individual ◽  
Geographical Locations ◽  
Over Time

Abstract In our days, energy issues belong to the most important problems facing the Earth and the solution may be expected partly from decreasing the amount of the energy used and partly from the increased utilisation of renewable energy resources. A substantial part of energy consumption is related to buildings and includes, inter alia, the use for cooling/heating, lighting and cooking purposes. In the view of the above, special attention has been paid to minimising the energy consumption of buildings since the late 1980s. Within the framework of that, the passive house was created, a building in which the thermal comfort can be achieved solely by postheating or postcooling of the fresh air mass without a need for recirculated air. The aim of the paper is to study the changes in the construction of passive houses over time. In addition, the differences between the geographical locations and the observable peculiarities with regard to the individual building types are also presented.

scholarly journals Video Observation of Perseids meteor shower 2016 from Egypt

2017 ◽  
Vol 2 (1) ◽  
pp. 151-156 ◽  
Author(s):  
G.F. Attia ◽  
A.M. Abdelaziz ◽  
I.N. Hassan
Keyword(s):  
Meteor Shower ◽  
Video Observation ◽  
Earth Atmosphere ◽  
Rapid Motion ◽  
The Earth ◽  
Video Observations

AbstractThe results of single television observations of Perseid meteor shower in 2016 are presented. The Perseid shower occurs from 17 July to 24 August, peaking on or around August 12 every year. In 2016, the peak of the Perseids was Night of Aug 11 to the morning of Aug 12. The meteor video observations in Egypt are carried out at The National Researcher Institute of Astronomy and Geophysics (NRIAG). The system consists of TV - cameras Watec -902H Ultimate with the lens DV10x8SA-1 (8-80 mm (10x)) capable of recording the rapid motion of meteors entering the Earth atmosphere.

Reconstructing the Crime

Impact! ◽  
1996 ◽  
Author(s):  
Gerrit L. Verschuur
Keyword(s):  
Spatial Diversity ◽  
Blast Waves ◽  
Meteor Showers ◽  
Rapid Succession ◽  
The Earth ◽  
The World ◽  
Cretaceous Period ◽  
The Impact ◽  
Mind's Eye ◽  
The Universe

Just what happened to the dinosaurs? In the mind’s eye, travel back to the Cretaceous period, 65 million years ago. First, land in a region of the world that will someday be called Oklahoma. You are in the era of dinosaurs, although there are no longer as many species about, worldwide, as there were ten million or so years before. In all, 23 species roam their individual parts of the planet. It is their lack of spatial diversity that will make them vulnerable to the catastrophe that is about to befall the earth. So imagine you are there, together with triceratops, stegosaurus, velociraptors, and tyrannosaurus rex. Mostly they live off the land, and some of them live off each other. On this day none of the animals on earth can possibly have any awareness that they are about to disappear. Such a luxury will only be granted to a conscious species that has learned to explore the universe. For those who survive the initial impact explosion and its immediate consequences, the coming months will mark a terrible example of one of Cuvier’s “brief periods of terror.” In rapid succession, all life will be subject to a holocaust of staggering proportion, horrendous blast waves, searing winds, showers of molten matter from the sky, earthquakes, a terrible darkness that will cut out sunlight for a year, and freezing weather that will last a decade. The ozone layer will be destroyed, and acid rain will make life intolerable for species that survived the first few months after the impact. You are there and you have been observing an odd phenomenon in the sky. For thousands of years a great comet has loomed, repeatedly lighting up the heavens with its glorious tail and then fading away to reappear a few years later. Long ago it was seen to break into fragments, each of which was a spectacular sight in its own right. Sometimes one of those fragments seemed to loom ever so close to the earth. For thousands of years, spectacular meteor showers have been seen whenever the earth passed through the tail of one of those comets, and sometimes dust drifted down into the atmosphere and disturbed the climate.

scholarly journals Investigation of the Motion of Periodic Comet Giacobini-Zinner and the Origin of the Draconid Meteor Showers of 1926, 1933 and 1946

1972 ◽  
Vol 45 ◽  
pp. 173-180
Author(s):  
Yu. V. Evdokimov
Keyword(s):  
Meteor Shower ◽  
Meteor Showers ◽  
Orbital Elements ◽  
Periodic Comet

Orbital elements of P/Giacobini-Zinner have been obtained from 577 observations at the eight apparitions 1900 to 1965 by linking apparitions in pairs. By this technique we established that the comet has a nongravitational secular deceleration amounting, on the average, to 0.081 day/(period)2. As a result of the comet's approach to Jupiter in 1969, a return of the Draconid meteor shower is possible on 1972 October 8d15h45m UT. The 1946 meteor shower was due to meteoroids ejected forward along the orbit of the comet in 1940 with velocities of 14 m s- 1. The meteor showers of 1933 and 1926 were apparently produced by meteoroids ejected in 1900 with velocities of 15.0 m s- 1 forward and 14.5 m s- 1 backward, respectively.

Occurrence and altitude of the non-specular long-lived meteor trails during meteor showers at high latitudes

2020 ◽  
Author(s):  
Alexander Kozlovsky ◽  
Renata Lukianova ◽  
Mark Lester
Keyword(s):  
Aerosol Particles ◽  
Height Distribution ◽  
High Latitudes ◽  
Meteor Showers ◽  
Height Difference ◽  
The Earth ◽  
Meteor Trails ◽  
June July ◽  
Two Parameters ◽  
Field Aligned Irregularities

<p>Meteoroids entering the Earth’s atmosphere produce ionized trails, which are detectable by radio sounding. Majority of such radar detections are the echoes from cylindrical ionized trails, which occur if the radar beam is perpendicular to the trail, i.e., the reflection is specular. Typically such echoes detected by VHF radars last less than one second. However, sometimes meteor radars (MR) observe unusually long-lived meteor echoes and these echoes are non-specular (LLNS echoes). The LLNS echoes last up to several tens of seconds and show highly variable amplitude of the radar return. The LLNS echoes are received from the non-field-aligned irregularities of ionization generated along trails of bright meteors and it is believed that key role in their generation belongs to the aerosol particles arising due to fragmentation and burning of large meteoroids. The occurrence and height distributions of LLNS are studied using MR observations at Sodankylä Geophysical Observatory (SGO, 67° 22' N, 26° 38' E, Finland) during 2008-2019. Two parameters are analyzed: the percentage and height distribution of LLNS echoes. These LLNS echoes constitute about 2% of all MR detections. However during certain meteor showers (Geminids, Perseids, Quadrantids, Arietids or/and Daytime ζ-Perseids, and Lyrids) the percentage of LLNS echoes is noticeably higher (about 6, 5, 4, 4, and 3%, respectively). Typically, the LLNSs occur ~2 km higher than other echoes (in June-July the height difference is reduced to ~1 km). Due to this elevation, a larger percentage of LLNSs is manifested as an upward shift of the height distribution of meteor trails during meteor showers. Moreover, during Lyrids, η-Aquariids, Perseids, Orionids, and Leonids the LLNS echoes occur noticeably, up to 3-6 km, higher than the echoes from other types of trails. Thus, enhanced heights of meteor detections during major meteor showers (Quadrantids, Lyrids, η-Aquariids, Arietids or/and Daytime ζ-Perseids, Perseids, Orionids, Leonids, and Geminids) are predominantly due to long-lived non-specular echoes from the non-field-aligned irregularities associated with large meteoroids.</p>

scholarly journals Metal concentrations in the upper atmosphere during meteor showers

2010 ◽  
Vol 10 (3) ◽  
pp. 909-917 ◽  
Author(s):  
J. Correira ◽  
A. C. Aikin ◽  
J. M. Grebowsky ◽  
J. P. Burrows
Keyword(s):  
Mass Flux ◽  
Mass Density ◽  
Meteor Shower ◽  
Meteor Showers ◽  
Vertical Column ◽  
Metal Concentrations ◽  
Theoretical Mass ◽  
Measuring Experiment ◽  
Dependent Mass ◽  
Temporal Profiles

Abstract. Using the nadir-viewing Global Ozone Measuring Experiment (GOME) UV/VIS spectrometer on the ERS-2 satellite, we investigate short term variations in the vertical magnesium column densities in the atmosphere and any connection to possible enhanced mass deposition during a meteor shower. Time-dependent mass influx rates are derived for all the major meteor showers using published estimates of mass density and temporal profiles of meteor showers. An average daily sporadic background mass flux rate is also calculated and used as a baseline against which calculated shower mass flux rates are compared. These theoretical mass flux rates are then compared with GOME derived metal vertical column densities of Mg and Mg+ from the years 1996–2001. There is no correlation between theoretical mass flux rates and changes in the Mg and Mg+ metal column densities. A possible explanation for the lack of a shower related increase in metal concentrations may be differences in the mass regimes dominating the average background mass flux and shower mass flux.

scholarly journals One-Pixel Views of Earth Reveal Seasonal Changes

Eos ◽  
2019 ◽  
Vol 97 ◽  
Author(s):  
Katherine Kornei
Keyword(s):  
Seasonal Changes ◽  
Satellite Images ◽  
The Earth ◽  
Single Pixel ◽  
Over Time

By averaging satellite images of the Earth down to a single pixel, researchers trace how the planet’s mean color varies over time, results that inform observations of distant exoplanets.

scholarly journals Metal concentrations in the upper atmosphere during meteor showers

2009 ◽  
Vol 9 (5) ◽  
pp. 18705-18726
Author(s):  
J. Correira ◽  
A. C. Aikin ◽  
J. M. Grebowsky ◽  
J. P. Burrows
Keyword(s):  
Mass Flux ◽  
Mass Density ◽  
Meteor Shower ◽  
Meteor Showers ◽  
Vertical Column ◽  
Metal Concentrations ◽  
Theoretical Mass ◽  
Measuring Experiment ◽  
Dependent Mass ◽  
Temporal Profiles

Abstract. Using the nadir-viewing Global Ozone Measuring Experiment (GOME) UV/VIS spectrometer on the ERS-2 satellite, we investigate short term variations in the vertical magnesium column densities in the atmosphere and any connection to possible enhanced mass deposition during a meteor shower. Time-dependent mass influx rates are derived for all the major meteor showers using published estimates of mass density and temporal profiles of meteor showers. An average daily sporadic background mass flux rate is also calculated and used as a baseline against which calculated shower mass flux rates are compared. These theoretical mass flux rates are then compared with GOME derived metal vertical column densities of Mg and Mg+ from the years 1996–2001. There is no correlation between theoretical mass flux rates and changes in the Mg and Mg+ metal column densities. A possible explanation for the lack of a shower related increase in metal concentrations may be differences in the mass regimes dominating the average background mass flux and shower mass flux.

43. Observations of the Leonid meteor shower in November 1966 in the U.S.S.R.

1968 ◽  
Vol 33 ◽  
pp. 440-445 ◽  
Author(s):  
V. A. Bronšten
Keyword(s):  
Soviet Union ◽  
Meteor Shower ◽  
Radar Observations ◽  
The Earth ◽  
The Soviet Union ◽  
Leonid Meteor Shower

In connection with the expected passage of the Earth through the densest part of the Leonid meteoric stream in November, 1966, the Commission on Comets and Meteors of the Astronomical Council of the U.S.S.R., and the All-Union Astronomical-Geodetic Society, organized visual, photographic and radar observations of the shower at many points in the Soviet Union.

scholarly journals Change of expansion characteristics of compacted soils used for dams in central Vietnam

2018 ◽  
Vol 193 ◽  
pp. 02003
Author(s):  
Quang Thanh Truong ◽  
Phan Ta Le ◽  
Thi Nhu Quynh Nguyen
Keyword(s):  
Soil Types ◽  
Test Analysis ◽  
Compacted Soils ◽  
Swelling Clays ◽  
The Earth ◽  
Central Vietnam ◽  
Swelling Rate ◽  
Swelling Characteristics ◽  
Swelling Coefficient ◽  
Over Time

Most of the earth embankments in central Vietnam are usually built with clays. Some types of clays in this area are swollen. If they are used to build dams, it can be detrimental to the embankment. Based on the results of laboratory test analysis, the authors investigated swelling characteristics of some soil types in the study area and found that the swelling rate of soil increases with the compaction of the soil sample. When swelling under pressure in approaching water over time, the swelling coefficient of the soil decreases significantly. Thus, swelling clays can be used to make dams, but they must be put in the appropriate position for the purpose of not swelling freely.

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