scholarly journals The Manifold Of Variations: impact location of short-term impactors

2021 ◽  
Vol 133 (6) ◽  
Author(s):  
Alessio Del Vigna ◽  
Linda Dimare ◽  
Davide Bracali Cioci
Keyword(s):  
Hazard Assessment ◽  
Orbit Determination ◽  
Close Approach ◽  
Dimensional Manifold ◽  
Two Dimensional ◽  
Short Term ◽  
Observational Dataset ◽  
Impact Location ◽  
The Earth ◽  
The Impact

AbstractThe interest in the problem of small asteroids observed shortly before a deep close approach or an impact with the Earth has grown a lot in recent years. Since the observational dataset of such objects is very limited, they deserve dedicated orbit determination and hazard assessment methods. The currently available systems are based on the systematic ranging, a technique providing a two-dimensional manifold of orbits compatible with the observations, the so-called Manifold Of Variations. In this paper we first review the Manifold Of Variations method, to then show how this set of virtual asteroids can be used to predict the impact location of short-term impactors, and compare the results with those of already existent methods.

Space-based platform asteroid orbit determination and collision warning

2020 ◽  
Author(s):  
Song yezhi
Keyword(s):  
Orbit Determination ◽  
Monitoring Network ◽  
Human Beings ◽  
Security Issue ◽  
Collision Warning ◽  
Common Space ◽  
Impact Location ◽  
Initial Orbit Determination ◽  
Celestial Bodies ◽  
The Impact

<p>The risk of asteroids impacting the earth is a common space security issue facing human beings. Since the ground-based monitoring network cannot cover the space area comprehensively, there are cases of celestial body out of monitoring. In response to this problem, this report studies the space-based platform's monitoring system, and calculates its performance for orbit determination and monitoring of small celestial bodies. For small celestial bodies that are not in the catalog, the initial orbit determination needs to be performed before the orbit improvement. In addition, this paper proposes a method based on Fibonacci search method to quickly predict the impact location of asteroids.</p>

Geoscience Authors and Reviewers during the COVID-19 Pandemic: Demographic Analysis of AGU's Authors and Peer Reviewers

2021 ◽  
Author(s):  
Paige Wooden ◽  
Brooks Hanson
Keyword(s):  
Science Research ◽  
Early Career ◽  
Demographic Analysis ◽  
Short Term ◽  
Early Career Researchers ◽  
The Earth ◽  
Peer Reviewing ◽  
Peer Reviewers ◽  
Rich Data ◽  
The Impact

<p>The COVID-19 pandemic has changed the way we work and live, and as of January 2020, the increase in cases and the initiation of the vaccine introduces even more uncertainty into the short-term future. With an increase in domestic responsibilities for many people, there is a heighted concern about the productivity of the Earth and space science research community, and especially the impact on student, early career researchers, and women. AGU's rich data has allowed us to investigate how the pandemic has affected our constituents, and in a poster presented at AGU 2020, we showed that submissions increased in 2020 with the same proportion of women submitting in 2020 and little monthly variation. Submissions from men and women in their 20s decreased in 2020 compared to 2019, while submissions from women in their 30s and 50s and men in their 40s increased.  We saw minor monthly fluctuations in submissions by the country-region of submitting author, with an increase in total and proportional submissions from China continuing from 2019. Additionally, our editors were concerned about the time the most affected scientists could devote to research and peer reviewing. This analysis seeks to update demographics of submitting authors with Q1 2021 data and introduce an analysis of the effect the pandemic had on our article peer reviewers. Preliminary analysis shows very little difference in the invite rates of women in 2020 compared to 2019 (+1%), and only a 0.4% decrease in women's accept to review rates in 2020 compared to 2019. We also only see slight monthly fluctuations in invite and review accept rates. Invitations to review by country of reviewer are proportionally similar in 2020 to those in 2019. This analysis will also investigate any changes in invited and agreed reviewer age to see how the pandemic may have influenced those likely to have research, teaching, and family commitments.</p>

Satellite thermal monitoring of Balkan region by means of Robust Satellite Techniques: the case of Albania (26 November 2019, Mw 6.4) earthquake

2020 ◽  
Author(s):  
Valerio Tramutoli ◽  
Nicola Genzano ◽  
Roberto Colonna ◽  
Carolina Filizzola ◽  
Mariano Lisi ◽  
...  
Keyword(s):  
Seismic Hazard Assessment ◽  
Statistical Correlation ◽  
Thermal Monitoring ◽  
Short Term ◽  
The Earth ◽  
Satellite Sensors ◽  
Balkan Region ◽  
Casual Relation ◽  
The Impact

<p>Since 2001, Robust Satellite Techniques (RST; Tramutoli 1998, 2007) has been used to study - by analyzing long-term TIR observations provided by passive satellite sensors - the enhancement of the Earth thermally emitted radiation, possibly related to seismic activities.</p><p>Such an approach has demonstrated to be able (especially when applied to geostationary satellite radiances) to isolate TIR anomalies possibly related to earthquake occurrence from those expected as a consequence of others natural (e.g. meteorological) or observational (e.g. measurement time and/or place) sources. Among the others TIR anomalies, those more significant (in term of Signal/Noise ratio), extended (in space) and persistent (in time) have been considered (SSTAs, Significant Sequence of TIR Anomalies, Eleftheriou et al., 2016) for further analyses. Up to now, long-term statistical correlation analyses between seismic events and RST-based SSTAs carried out in different European seismic regions (i.e. Greece, Italy and Turkey by using MSG-SEVIRI) highlights that the 75% of SSTAs are in apparent space-time relation with earthquakes with magnitude greater than 4. In all testing regions/periods a non-casual relation has been found.</p><p>In this paper, we will show the results achieved by real-time thermal monitoring over Albania region at time of the strong earthquake of magnitude Mw 6.4 occurred on 26 November 2019. Moreover, we will discuss about the impact of the use of the "RST-based satellite TIR anomalies" parameter in the framework a multi-parametric system devote to the seismic hazard assessment in the short-term.</p>

A Novel Approach to Asteroid Impact Monitoring

2021 ◽  
Vol 162 (6) ◽  
pp. 277
Author(s):  
Javier Roa ◽  
Davide Farnocchia ◽  
Steven R. Chesley
Keyword(s):  
Parameter Space ◽  
Orbit Determination ◽  
Close Approach ◽  
Asteroid Impact ◽  
Impact Monitoring ◽  
Novel Approach ◽  
Virtual Impactors ◽  
Non Gaussian ◽  
The Impact ◽  
Nongravitational Forces

Abstract Orbit-determination programs find the orbit solution that best fits a set of observations by minimizing the root mean square of the residuals of the fit. For near-Earth asteroids, the uncertainty of the orbit solution may be compatible with trajectories that impact Earth. This paper shows how incorporating the impact condition as an observation in the orbit-determination process results in a robust technique for finding the so-called virtual impactors, i.e., the regions in parameter space leading to impacts. The impact pseudo-observation residuals are the b-plane coordinates at the time of close approach and the uncertainty is set to a fraction of the Earth radius. The extended orbit-determination filter converges naturally to an impacting solution if allowed by the observations. The uncertainty of the resulting orbit provides an excellent geometric representation of the virtual impactor. As a result, the impact probability can be efficiently estimated by exploring this region in parameter space using importance sampling. The proposed technique can systematically handle a large number of estimated parameters, account for nongravitational forces, deal with nonlinearities, and correct for non-Gaussian initial uncertainty distributions. The algorithm has been implemented into a new impact-monitoring system at JPL called Sentry-II, after undergoing extensive testing. The main advantages of Sentry-II over the previous Sentry system are that Sentry-II can systematically process orbits perturbed by nongravitational forces and that it is generally more robust when dealing with pathological cases. The run times and completeness of both systems are comparable, with the impact probability of Sentry-II for 99% completeness being 3 × 10−7.

scholarly journals Transforming Environmental Awareness of Students Through the Arts and Place-Based Pedagogies

2016 ◽  
Vol 9 (2) ◽  
pp. 239-260 ◽  
Author(s):  
Tonia Gray ◽  
Cameron Thomson
Keyword(s):  
Natural World ◽  
Short Term ◽  
Socially Responsible ◽  
Modus Operandi ◽  
Young Learners ◽  
The Earth ◽  
The Arts ◽  
Outdoor Setting ◽  
Enrichment Program ◽  
The Impact

Incorporating the Arts into immersive place-based education programs can increase connectivity with the environment and facilitate the development of socially responsible and pro-environmental learners. Increasingly, children and adolescents are alienated and detached from the natural world. Given this noticeable shift, educators working in the outdoor setting need to rethink their modus operandi. Past attempts to promote learner connection with the environment have centred upon short-term stays and risk-centric approaches that embrace high adrenaline activities. This is the antithesis of Touched By The Earth, a yearlong place-based enrichment program using multi-modal creative methods with young learners to delve into the impact of experiential learning and how the Arts promote a personal relationship with the environment.

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.

A Newspaper’s Effect on the Strength of Automatic Associations in Memory

2012 ◽  
Vol 24 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Florian Arendt
Keyword(s):  
Treatment Group ◽  
Term Effect ◽  
Control Group ◽  
Implicit Measure ◽  
Short Term ◽  
Short Term Treatment ◽  
Short Term Effect ◽  
Automatic Associations ◽  
Foreign Nationality ◽  
The Impact

A test was done to see if reading a newspaper which consistently overrepresents foreigners as criminals strengthens the automatic association between foreign country and criminal in memory (i.e., implicit cultivation). Further, an investigation was done to find out if reading articles from the same newspaper produces a short-term effect on the same measure and if (1) emotionalization of the newspaper texts, (2) emotional reactions of the reader (indicated by arousal), and (3) attributed text credibility moderate the short-term treatment effect. Eighty-five participants were assigned to one of three experimental conditions. Participants in the control group received short factual crime texts, where the nationality of the offender was not mentioned. Participants in the factual treatment group received the same texts, but the foreign nationality was mentioned. Participants in the emotionalized treatment group received emotionalized articles (i.e., texts which are high in vividness and frequency) covering the same crimes, with the foreign nationality mentioned. Supporting empirical evidence for implicit cultivation and a short-term effect was found. However, only emotionalized articles produced a short-term effect on the strength of the automatic association, indicating that newspaper texts must have a minimum of stimulus intensity to overcome an effect threshold. There were no moderating effects of arousal or credibility pertaining to the impact on the implicit measure. However, credibility moderated the short-term effect on a first-order judgment (i.e., estimated frequency of foreigners of all criminals). This indicates that a newspaper’s effect on the strength of automatic associations is relatively independent from processes of propositional reasoning.

Diatoms in the Amur Bay sediments (Sea of Japan) and the impact of typhoons on their accumulation over the last 2000 years

2019 ◽  
pp. 252-256
Author(s):  
Irina A. Prushkovskaya ◽  
Ira B. Tsoy
Keyword(s):  
Sea Of Japan ◽  
Short Term ◽  
Catastrophic Events ◽  
Bromine Content ◽  
Amur Bay ◽  
The Impact

The study of diatoms in the sediments of the Amur Bay (Sea of Japan), formed over the last 2000 years, showed that the sharp short-term drops in the concentration of diatoms coincide with the minima of bromine content, which can be explained by the influence of typhoons or other catastrophic events leading to floods and used later in paleoreconstructions.

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