R. Joseph, O. Planchon, N. Duxbury, K. Latif, G. Kidron, L. Consorti, R. Armstrong, Carl H. Gibson, Rudolph E. Schild
Billions of years ago, the Northern Hemisphere of Mars may have been covered by at least one ocean and thousands of lakes and rivers. These findings, based initially on telescopic observations and images by the Mariner and Viking missions, led investigators to hypothesize that stromatolite fashioning cyanobacteria may have proliferated in the surface waters, and life may have been successfully transferred between Earth and Mars via tons of debris ejected into the space following bolide impact. Studies conducted by NASA’s robotic rovers also indicate that Mars was wet and habitable and may have been inhabited in the ancient past. It has been hypothesized that Mars subsequently lost its magnetic field, oceans, and atmosphere when bolides negatively impacted its geodynamo and that the remnants of the Martian seas began to evaporate and became frozen beneath the surface. As reviewed here, twenty-five investigators have published evidence of Martian sedimentary structures that resemble microbial mats and stromatolites, which may have been constructed billions of years ago on ancient lake shores and in receding bodies of water, although if these formations are abiotic or biotic is unknown. These findings parallel the construction of the first stromatolites on Earth. The evidence reviewed here does not prove but supports the hypothesis that ancient Mars had oceans (as well as lakes) and was habitable and inhabited, and life may have been transferred between Earth and Mars billions of years ago due to powerful solar winds and life-bearing ejecta propelled into the space following the bolide impact.
{"title":"Oceans, Lakes, and Stromatolites on Mars","authors":"R. Joseph, O. Planchon, N. Duxbury, K. Latif, G. Kidron, L. Consorti, R. Armstrong, Carl H. Gibson, Rudolph E. Schild","doi":"10.1155/2020/6959532","DOIUrl":"https://doi.org/10.1155/2020/6959532","url":null,"abstract":"Billions of years ago, the Northern Hemisphere of Mars may have been covered by at least one ocean and thousands of lakes and rivers. These findings, based initially on telescopic observations and images by the Mariner and Viking missions, led investigators to hypothesize that stromatolite fashioning cyanobacteria may have proliferated in the surface waters, and life may have been successfully transferred between Earth and Mars via tons of debris ejected into the space following bolide impact. Studies conducted by NASA’s robotic rovers also indicate that Mars was wet and habitable and may have been inhabited in the ancient past. It has been hypothesized that Mars subsequently lost its magnetic field, oceans, and atmosphere when bolides negatively impacted its geodynamo and that the remnants of the Martian seas began to evaporate and became frozen beneath the surface. As reviewed here, twenty-five investigators have published evidence of Martian sedimentary structures that resemble microbial mats and stromatolites, which may have been constructed billions of years ago on ancient lake shores and in receding bodies of water, although if these formations are abiotic or biotic is unknown. These findings parallel the construction of the first stromatolites on Earth. The evidence reviewed here does not prove but supports the hypothesis that ancient Mars had oceans (as well as lakes) and was habitable and inhabited, and life may have been transferred between Earth and Mars billions of years ago due to powerful solar winds and life-bearing ejecta propelled into the space following the bolide impact.","PeriodicalId":48962,"journal":{"name":"Advances in Astronomy","volume":"2020 1","pages":"6959532"},"PeriodicalIF":1.4,"publicationDate":"2020-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2020/6959532","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46729476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nucleonic direct Urca processes and cooling of the massive neutron stars are studied by considering antikaon condensations. Calculations are performed in the relativistic mean field and isothermal interior approximations. Neutrino energy losses of the nucleonic direct Urca processes are reduced when the optical potential of antikaons changes from to MeV. If the center density of the massive neutron stars is a constant, the masses taper off with the optical potential of antikaons, and neutrino luminosities of the nucleonic direct Urca processes decrease for but first increase and then decrease for larger . Large optical potential of antikaons results in warming of the nonsuperfluid massive neutron stars. Massive neutron stars turn warmer with the protonic superfluids. However, the decline of the critical temperatures of the protonic superfluids for the large optical potential of antikaons can speed up the cooling of the massive neutron stars.
{"title":"Nucleonic Direct Urca Processes and Cooling of the Massive Neutron Star by Antikaon Condensations","authors":"Yan Xu, W. Ding, Cheng-zhi Liu, J. Han","doi":"10.1155/2020/6146913","DOIUrl":"https://doi.org/10.1155/2020/6146913","url":null,"abstract":"Nucleonic direct Urca processes and cooling of the massive neutron stars are studied by considering antikaon condensations. Calculations are performed in the relativistic mean field and isothermal interior approximations. Neutrino energy losses of the nucleonic direct Urca processes are reduced when the optical potential of antikaons changes from to MeV. If the center density of the massive neutron stars is a constant, the masses taper off with the optical potential of antikaons, and neutrino luminosities of the nucleonic direct Urca processes decrease for but first increase and then decrease for larger . Large optical potential of antikaons results in warming of the nonsuperfluid massive neutron stars. Massive neutron stars turn warmer with the protonic superfluids. However, the decline of the critical temperatures of the protonic superfluids for the large optical potential of antikaons can speed up the cooling of the massive neutron stars.","PeriodicalId":48962,"journal":{"name":"Advances in Astronomy","volume":"2020 1","pages":"6146913"},"PeriodicalIF":1.4,"publicationDate":"2020-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2020/6146913","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42875599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, the problem of the slow spinning motion of a rigid body about a point O, being fixed in space, in the presence of the Newtonian force field and external torque is considered. We achieve the slow spin by giving the body slow rotation with a sufficiently small angular velocity component about the moving z-axis. We obtain the periodic solutions in a new domain of the angular velocity vector component , define a large parameter proportional to , and use the technique of the large parameter for solving this problem. Geometric interpretations of motions will be illustrated. Comparison of the results with the previous works is considered. A discussion of obtained solutions and results is presented.
{"title":"The Slow Spinning Motion of a Rigid Body in Newtonian Field and External Torque","authors":"A. I. Ismail","doi":"10.1155/2020/4179590","DOIUrl":"https://doi.org/10.1155/2020/4179590","url":null,"abstract":"In this paper, the problem of the slow spinning motion of a rigid body about a point O, being fixed in space, in the presence of the Newtonian force field and external torque is considered. We achieve the slow spin by giving the body slow rotation with a sufficiently small angular velocity component about the moving z-axis. We obtain the periodic solutions in a new domain of the angular velocity vector component , define a large parameter proportional to , and use the technique of the large parameter for solving this problem. Geometric interpretations of motions will be illustrated. Comparison of the results with the previous works is considered. A discussion of obtained solutions and results is presented.","PeriodicalId":48962,"journal":{"name":"Advances in Astronomy","volume":"2020 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2020/4179590","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45567650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The small parameter method was applied for solving many rotational motions of heavy solids, rigid bodies, and gyroscopes for different problems which classify them according to certain initial conditions on moments of inertia and initial angular velocity components. For achieving the small parameter method, the authors have assumed that the initial angular velocity is sufficiently large. In this work, it is assumed that the initial angular velocity is sufficiently small to achieve the large parameter instead of the small one. In this manner, a lot of energy used for making the motion initially is saved. The obtained analytical periodic solutions are represented graphically using a computer program to show the geometric periodicity of the obtained solutions in some interval of time. In the end, the geometric interpretation of the stability of a motion is given.
{"title":"Solving a Problem of Rotary Motion for a Heavy Solid Using the Large Parameter Method","authors":"A. I. Ismail","doi":"10.1155/2020/2764867","DOIUrl":"https://doi.org/10.1155/2020/2764867","url":null,"abstract":"The small parameter method was applied for solving many rotational motions of heavy solids, rigid bodies, and gyroscopes for different problems which classify them according to certain initial conditions on moments of inertia and initial angular velocity components. For achieving the small parameter method, the authors have assumed that the initial angular velocity is sufficiently large. In this work, it is assumed that the initial angular velocity is sufficiently small to achieve the large parameter instead of the small one. In this manner, a lot of energy used for making the motion initially is saved. The obtained analytical periodic solutions are represented graphically using a computer program to show the geometric periodicity of the obtained solutions in some interval of time. In the end, the geometric interpretation of the stability of a motion is given.","PeriodicalId":48962,"journal":{"name":"Advances in Astronomy","volume":"2020 1","pages":"1-7"},"PeriodicalIF":1.4,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2020/2764867","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48640934","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The present work aims at constructing an atlas of the balanced Earth satellite orbits with respect to the secular and long periodic effects of Earth oblateness with the harmonics of the geopotential retained up to the 4th zonal harmonic. The variations of the elements are averaged over the fast and medium angles, thus retaining only the secular and long periodic terms. The models obtained cover the values of the semi-major axis from 1.1 to 2 Earth’s radii, although this is applicable only for 1.1 to 1.3 Earth’s radii due to the radiation belts. The atlas obtained is useful for different purposes, with those having the semi-major axis in this range particularly for remote sensing and meteorology.
{"title":"Balanced Low Earth Satellite Orbits","authors":"A. Mostafa, M. H. El Dewaik","doi":"10.1155/2020/7421396","DOIUrl":"https://doi.org/10.1155/2020/7421396","url":null,"abstract":"The present work aims at constructing an atlas of the balanced Earth satellite orbits with respect to the secular and long periodic effects of Earth oblateness with the harmonics of the geopotential retained up to the 4th zonal harmonic. The variations of the elements are averaged over the fast and medium angles, thus retaining only the secular and long periodic terms. The models obtained cover the values of the semi-major axis from 1.1 to 2 Earth’s radii, although this is applicable only for 1.1 to 1.3 Earth’s radii due to the radiation belts. The atlas obtained is useful for different purposes, with those having the semi-major axis in this range particularly for remote sensing and meteorology.","PeriodicalId":48962,"journal":{"name":"Advances in Astronomy","volume":" ","pages":"1-12"},"PeriodicalIF":1.4,"publicationDate":"2020-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45360776","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A derivation of Cosmological Age explicitly constrained by Cosmic Microwave Background Radiation (CMBR) is presented, demonstrating that the correct value of Cosmological Age is equal to the Hubble Age. It is shown that utilizing “z = 0” for Cosmological Redshift in the Present Epoch introduces a fundamental flaw into Cosmological Age calculations. However, this flaw is captured and corrected by the Polarizable-Vacuum (PV) Model of Gravity developed by Puthoff, suggesting that the Dark Energy Field exists as a massive photonic field. Consequently, it is demonstrated that for a Dark Energy Driven description of Accelerated Cosmological Expansion, Cosmological Redshift takes a negative value in the Present Epoch.
{"title":"The Existence and Effect of Dark Energy Redshift on Cosmological Age","authors":"R. Storti","doi":"10.1155/2020/2436965","DOIUrl":"https://doi.org/10.1155/2020/2436965","url":null,"abstract":"A derivation of Cosmological Age explicitly constrained by Cosmic Microwave Background Radiation (CMBR) is presented, demonstrating that the correct value of Cosmological Age is equal to the Hubble Age. It is shown that utilizing “z = 0” for Cosmological Redshift in the Present Epoch introduces a fundamental flaw into Cosmological Age calculations. However, this flaw is captured and corrected by the Polarizable-Vacuum (PV) Model of Gravity developed by Puthoff, suggesting that the Dark Energy Field exists as a massive photonic field. Consequently, it is demonstrated that for a Dark Energy Driven description of Accelerated Cosmological Expansion, Cosmological Redshift takes a negative value in the Present Epoch.","PeriodicalId":48962,"journal":{"name":"Advances in Astronomy","volume":"2020 1","pages":"2436965"},"PeriodicalIF":1.4,"publicationDate":"2020-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2020/2436965","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46525801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
B. Benhammouda, A. Mansur, M. Shoaib, I. Szücs-Csillik, D. Offin
In the current article, we study the kite four-body problems with the goal of identifying global regions in the mass parameter space which admits a corresponding central configuration of the four masses. We consider two different types of symmetrical configurations. In each of the two cases, the existence of a continuous family of central configurations for positive masses is shown. We address the dynamical aspect of periodic solutions in the settings considered and show that the minimizers of the classical action functional restricted to the homographic solutions are the Keplerian elliptical solutions. Finally, we provide numerical explorations via Poincare cross-sections, to show the existence of periodic and quasiperiodic solutions within the broader dynamical context of the four-body problem.
{"title":"Central Configurations and Action Minimizing Orbits in Kite Four-Body Problem","authors":"B. Benhammouda, A. Mansur, M. Shoaib, I. Szücs-Csillik, D. Offin","doi":"10.1155/2020/5263750","DOIUrl":"https://doi.org/10.1155/2020/5263750","url":null,"abstract":"In the current article, we study the kite four-body problems with the goal of identifying global regions in the mass parameter space which admits a corresponding central configuration of the four masses. We consider two different types of symmetrical configurations. In each of the two cases, the existence of a continuous family of central configurations for positive masses is shown. We address the dynamical aspect of periodic solutions in the settings considered and show that the minimizers of the classical action functional restricted to the homographic solutions are the Keplerian elliptical solutions. Finally, we provide numerical explorations via Poincare cross-sections, to show the existence of periodic and quasiperiodic solutions within the broader dynamical context of the four-body problem.","PeriodicalId":48962,"journal":{"name":"Advances in Astronomy","volume":"2020 1","pages":"1-18"},"PeriodicalIF":1.4,"publicationDate":"2020-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2020/5263750","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41545920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kai Wang, Mao-zheng Chen, Jun Ma, X. Duan, Yang Wang, Liang Cao, Hao Yan, B. Xiang
The receiver is a signal receiving device in a radio telescope system. As an important parameter to characterize the receiver performance, noise temperature is very practical to calibrate accurately. The traditional receiver noise temperature calibration method is the cold and ambient load method. Through the establishment of K-band ambient receiver, and its amplitude calibration test platform of the cold and ambient load method, chopper wheel method, and ambient and hot load method, comparison and analysis of the above three methods were carried out. The test and calculation results show that the test accuracy of the cold and ambient load method is about 1.3%, that of the chopper wheel method (nonlow elevation) is about 3%, and that of the ambient and hot load method is about 9%. The test accuracy of the ambient and hot load method is slightly lower than that of the above two methods. The analysis is mainly due to the uncertainty of the hot load temperature and the small temperature difference between the two loads, which leads to the deterioration of the overall accuracy. But the advantage is that the method can perform real-time calibration in the process of observation, and it is easier to implement than the traditional cold and ambient load method. The results of noise temperature measurement are compared with those of theoretical calculation, the error is basically within 10%, and it can satisfy the demand of the noise temperature test. In the future, we expect that on the basis of increasing the hot load temperature, further experiments were carried out on the thermostatic treatment of hot load and the accuracy of temperature acquisition, and finally we hope that this method can better meet the testing requirements of receiver noise temperature and radio source amplitude calibration.
{"title":"Analysis and Research on the Centimeter Band Receiver Amplitude Calibration Method","authors":"Kai Wang, Mao-zheng Chen, Jun Ma, X. Duan, Yang Wang, Liang Cao, Hao Yan, B. Xiang","doi":"10.1155/2020/8484610","DOIUrl":"https://doi.org/10.1155/2020/8484610","url":null,"abstract":"The receiver is a signal receiving device in a radio telescope system. As an important parameter to characterize the receiver performance, noise temperature is very practical to calibrate accurately. The traditional receiver noise temperature calibration method is the cold and ambient load method. Through the establishment of K-band ambient receiver, and its amplitude calibration test platform of the cold and ambient load method, chopper wheel method, and ambient and hot load method, comparison and analysis of the above three methods were carried out. The test and calculation results show that the test accuracy of the cold and ambient load method is about 1.3%, that of the chopper wheel method (nonlow elevation) is about 3%, and that of the ambient and hot load method is about 9%. The test accuracy of the ambient and hot load method is slightly lower than that of the above two methods. The analysis is mainly due to the uncertainty of the hot load temperature and the small temperature difference between the two loads, which leads to the deterioration of the overall accuracy. But the advantage is that the method can perform real-time calibration in the process of observation, and it is easier to implement than the traditional cold and ambient load method. The results of noise temperature measurement are compared with those of theoretical calculation, the error is basically within 10%, and it can satisfy the demand of the noise temperature test. In the future, we expect that on the basis of increasing the hot load temperature, further experiments were carried out on the thermostatic treatment of hot load and the accuracy of temperature acquisition, and finally we hope that this method can better meet the testing requirements of receiver noise temperature and radio source amplitude calibration.","PeriodicalId":48962,"journal":{"name":"Advances in Astronomy","volume":"2020 1","pages":"1-10"},"PeriodicalIF":1.4,"publicationDate":"2020-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2020/8484610","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43422010","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Advances in Astronomy is pleased to announce the appointment of Prof Josep Trigo Rodríguez as its new Chief Editor. In this Editorial, Prof Trigo introduces himself, describes some of the journal’s journey and current status, and shares his vision and aspirations for its future.
{"title":"Introducing Our New Chief Editor","authors":"J. Trigo-Rodríguez","doi":"10.1155/2020/7382029","DOIUrl":"https://doi.org/10.1155/2020/7382029","url":null,"abstract":"Advances in Astronomy is pleased to announce the appointment of Prof Josep Trigo Rodríguez as its new Chief Editor. In this Editorial, Prof Trigo introduces himself, describes some of the journal’s journey and current status, and shares his vision and aspirations for its future.","PeriodicalId":48962,"journal":{"name":"Advances in Astronomy","volume":" ","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43828188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Feng Wang, W. Cao, D. Bastieri, J. Fan, Chenzhou Cui
{"title":"Astronomical Massive Data Processing Technology","authors":"Feng Wang, W. Cao, D. Bastieri, J. Fan, Chenzhou Cui","doi":"10.1155/2020/6848935","DOIUrl":"https://doi.org/10.1155/2020/6848935","url":null,"abstract":"","PeriodicalId":48962,"journal":{"name":"Advances in Astronomy","volume":"1 1","pages":""},"PeriodicalIF":1.4,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2020/6848935","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42395565","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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