In the article 'Evolution Model of the Earth’s Limited Expanding' published in Volume 45 Number (4) of Chinese Science Bulletin[1], the author suggests that the earth expands according to a law R(t) = R0+A(1 ...In the article 'Evolution Model of the Earth’s Limited Expanding' published in Volume 45 Number (4) of Chinese Science Bulletin[1], the author suggests that the earth expands according to a law R(t) = R0+A(1 -exp(β(t-ts))) (remark: this formula was mistakenly printed as R(t) = R0 + Aexp(β(t-ts)) in the and formula (12) of the text of ref. [1]). According to ref. [1], the earth was formed 4.6 billion years ago. After 0.3 billion years from its birth (ts), it started expansion from an initial radius R0 of 4651 km, and may reach a final maximum radius of R0+A = 6511 km. In the 4.6 billion years history, the radius of the earch has increased by 1720 km, or the density decreased from 14200 km/m3 (2.57 times the present density) to 5520 kg/m3 within the latest 4.3 billion years.展开更多
Although previous studies have analyzed the unique structural characteristics of the polar vortices on Earth,Venus,Mars,and Titan,the understanding of the polar vortices on Venus and Titan is primarily based on small-...Although previous studies have analyzed the unique structural characteristics of the polar vortices on Earth,Venus,Mars,and Titan,the understanding of the polar vortices on Venus and Titan is primarily based on small-scale case studies due to the limited resolution and coverage of observational data.Conducting a detailed comparison of the polar vortex characteristics between the major terrestrial planets and Titan in the solar system is more challenging.In order to more finely compare the polar vortex characteristics of the main terrestrial planets in the solar system with Titan,we have achieved the optimal estimation of the polar vortices of Venus and Titan under existing conditions based on the advanced VCD2.3 and TitanWRF model.At the same time,combining ERA5 and EMARS databases,a detailed spatiotemporal comparison of polar vortex characteristics between terrestrial planets with atmospheres in the solar system and the most Earth-like Titan satellite was conducted for the first time.Here,we demonstrate that:(1)The circulation characteristics of Mars above the 1 mbar level are very similar to those at 1000 mbar in the lower layers of Titan,with seasonal variations of the same height.(2)In contrast to the vortex structure that is stably maintained in the lead direction in the polar regions of Mars and Earth during the winter,the time of occurrence of the peak vortex intensity at Titan and Venus is gradually shifted forward with increasing altitude.(3)When Venus undergoes vortex instability drift,the polar vortex at an altitude of 1 mbar breaks up into banded structures,a phenomenon that closely resembles the twisting deformation of PV structures during weak stratospheric polar vortex events on Earth.展开更多
On airless bodies such as the Moon and Mercury, secondary craters on the continuous secondaries facies of fresh craters mostly occur in chains and clusters. They have very irregular shapes. Secondaries on the continuo...On airless bodies such as the Moon and Mercury, secondary craters on the continuous secondaries facies of fresh craters mostly occur in chains and clusters. They have very irregular shapes. Secondaries on the continuous secondaries facies of some Martian and Mercurian craters are more isolated from each other in distribution and are more circular in shape, probably due to the effect of target properties on the impact excavation process. This paper studies secondaries on the continuous secondaries facies of all fresh lunar complex craters using recently-obtained high resolution images. After a global search, we find that 3 impact craters and basins on the Moon have circular and isolated secondaries on the continuous secondaries facies similar to those on Mercury： the Orientale basin, the Antoniadi crater, and the Compton crater. The morphological differences between such special secondaries and typical lunar secondaries are quantitatively compared and analyzed. Our preliminary analyses suggest that the special secondaries were probably caused by high temperature gradients within the local targets when these craters and basins formed. The high-temperature of the targets could have affected the impact excavation process by causing higher ejection angles, giving rise to more scattered circular secondaries.展开更多
基金the National Natural Science Foundation of China (Grant No. 49774236),
文摘In the article 'Evolution Model of the Earth’s Limited Expanding' published in Volume 45 Number (4) of Chinese Science Bulletin[1], the author suggests that the earth expands according to a law R(t) = R0+A(1 -exp(β(t-ts))) (remark: this formula was mistakenly printed as R(t) = R0 + Aexp(β(t-ts)) in the and formula (12) of the text of ref. [1]). According to ref. [1], the earth was formed 4.6 billion years ago. After 0.3 billion years from its birth (ts), it started expansion from an initial radius R0 of 4651 km, and may reach a final maximum radius of R0+A = 6511 km. In the 4.6 billion years history, the radius of the earch has increased by 1720 km, or the density decreased from 14200 km/m3 (2.57 times the present density) to 5520 kg/m3 within the latest 4.3 billion years.
文摘Although previous studies have analyzed the unique structural characteristics of the polar vortices on Earth,Venus,Mars,and Titan,the understanding of the polar vortices on Venus and Titan is primarily based on small-scale case studies due to the limited resolution and coverage of observational data.Conducting a detailed comparison of the polar vortex characteristics between the major terrestrial planets and Titan in the solar system is more challenging.In order to more finely compare the polar vortex characteristics of the main terrestrial planets in the solar system with Titan,we have achieved the optimal estimation of the polar vortices of Venus and Titan under existing conditions based on the advanced VCD2.3 and TitanWRF model.At the same time,combining ERA5 and EMARS databases,a detailed spatiotemporal comparison of polar vortex characteristics between terrestrial planets with atmospheres in the solar system and the most Earth-like Titan satellite was conducted for the first time.Here,we demonstrate that:(1)The circulation characteristics of Mars above the 1 mbar level are very similar to those at 1000 mbar in the lower layers of Titan,with seasonal variations of the same height.(2)In contrast to the vortex structure that is stably maintained in the lead direction in the polar regions of Mars and Earth during the winter,the time of occurrence of the peak vortex intensity at Titan and Venus is gradually shifted forward with increasing altitude.(3)When Venus undergoes vortex instability drift,the polar vortex at an altitude of 1 mbar breaks up into banded structures,a phenomenon that closely resembles the twisting deformation of PV structures during weak stratospheric polar vortex events on Earth.
基金supported by National Natural Science Foundation of China (Nos. 41403053, J1210043)fund CUG130106 of China University of Geosciences (Wuhan)
文摘On airless bodies such as the Moon and Mercury, secondary craters on the continuous secondaries facies of fresh craters mostly occur in chains and clusters. They have very irregular shapes. Secondaries on the continuous secondaries facies of some Martian and Mercurian craters are more isolated from each other in distribution and are more circular in shape, probably due to the effect of target properties on the impact excavation process. This paper studies secondaries on the continuous secondaries facies of all fresh lunar complex craters using recently-obtained high resolution images. After a global search, we find that 3 impact craters and basins on the Moon have circular and isolated secondaries on the continuous secondaries facies similar to those on Mercury： the Orientale basin, the Antoniadi crater, and the Compton crater. The morphological differences between such special secondaries and typical lunar secondaries are quantitatively compared and analyzed. Our preliminary analyses suggest that the special secondaries were probably caused by high temperature gradients within the local targets when these craters and basins formed. The high-temperature of the targets could have affected the impact excavation process by causing higher ejection angles, giving rise to more scattered circular secondaries.
