Four future missions for deep space exploration and future space-based exoplanet surveys on habitable planets by 2030 are scheduled to be launched.Two Mars exploration missions are designed to investigate geological s...Four future missions for deep space exploration and future space-based exoplanet surveys on habitable planets by 2030 are scheduled to be launched.Two Mars exploration missions are designed to investigate geological structure,the material on Martian surface,and retrieve returned samples.The asteroids and main belt comet exploration is expected to explore two objects within 10 years.The small-body mission will aim to land on the asteroid and get samples return to Earth.The basic physical characteristics of the two objects will be obtained through the mission.The exploration of Jupiter system will characterize the environment of Jupiter and the four largest Moons and understand the atmosphere of Jupiter.In addition,we further introduce two space-based exoplanet survey by 2030,Miyin Program and Closeby Habitable Exoplanet Survey(CHES Mission).Miyin program aims to detect habitable exoplanets using interferometry,while CHES mission expects to discover habitable exoplanets orbiting FGK stars within 10 pc through astrometry.The above-mentioned missions are positively to achieve breakthroughs in the field of planetary science.展开更多
We model the interior of Europa using a method by which we set three layers of Europa and the composition of each layer in advance. Comparing the calculated mass and radius related to each model with the data derived ...We model the interior of Europa using a method by which we set three layers of Europa and the composition of each layer in advance. Comparing the calculated mass and radius related to each model with the data derived by the observations, we propose three possible internal structure models for Europa. All models are assumed to be differentiated into a metallic core, a (Mg,Fe)2SiO4 silicate mantle and an outer water shell. The only difference amongst these models are the composition of the core. The core of Model I is composed of Fe, while Model II composed of FeS, and the two models are based on the inferences provided by Europa's external gravitational field. Model III has a core which consists of Fe-FeS alloy, similar to that of Earth's outer core. Model I has a Fe core with a radius of 431 km, a (Mg,Fe)2SiO4 mantle with 999 km and a water shell with 132 km. Model II has a 777 km FeS core, a 619 km (Mg,Fe)2SiO4 mantle and a 167 km water shell. Model III has a 571 km Fe0.8(FeS)0.2 core, a 832 km (Mg,Fe)2SiO4 mantle and a 166 km water shell. In all three models, the density range and the radius of each layer is consistent with those deduced by Anderson et al.展开更多
We perform numerical simulations to investigate tidal evolution of two single-planet systems,that is,WASP-50 and GJ 1214 and a two-planet system CoRoT-7.The results of orbital evolution show that tidal decay and circu...We perform numerical simulations to investigate tidal evolution of two single-planet systems,that is,WASP-50 and GJ 1214 and a two-planet system CoRoT-7.The results of orbital evolution show that tidal decay and circularization may play a significant role in shaping their final orbits,which is related to the initial orbital data in the simulations.For GJ 1214 system,different cases of initial eccentricity are also considered as only an upper limit of its eccentricity(0.27) is shown,and the outcome suggests a possible maximum initial eccentricity(0.4) in the adopted dynamical model.Moreover,additional runs with alternative values of dissipation factor Q1 are carried out to explore tidal evolution for GJ 1214b,and these results further indicate that the real Q1 of GJ 1214b may be much larger than its typical value,which may reasonably suggest that GJ 1214b bears a present-day larger eccentricity,undergoing tidal circularization at a slow rate.For the CoRoT-7 system,tidal forces make two planets migrating towards their host star as well as producing tidal circularization,and in this process tidal effects and mutual gravitational interactions are coupled with each other.Various scenarios of the initial eccentricity of the outer planet have also been done to investigate final planetary configuration.Tidal decay arising from stellar tides may still work for each system as the eccentricity decreases to zero,and this is in association with the remaining lifetime of each planet used to predict its future.展开更多
基金Supported by the B-type Strategic Priority Program of the Chinese Academy of Sciences(XDB41000000)the National Natural Science Foundation of China(11773081,11573073)CAS Interdisciplinary Innovation Team,Foundation of Minor Planets of the Purple Mountain Observatory and Youth Innovation Promotion Association。
文摘Four future missions for deep space exploration and future space-based exoplanet surveys on habitable planets by 2030 are scheduled to be launched.Two Mars exploration missions are designed to investigate geological structure,the material on Martian surface,and retrieve returned samples.The asteroids and main belt comet exploration is expected to explore two objects within 10 years.The small-body mission will aim to land on the asteroid and get samples return to Earth.The basic physical characteristics of the two objects will be obtained through the mission.The exploration of Jupiter system will characterize the environment of Jupiter and the four largest Moons and understand the atmosphere of Jupiter.In addition,we further introduce two space-based exoplanet survey by 2030,Miyin Program and Closeby Habitable Exoplanet Survey(CHES Mission).Miyin program aims to detect habitable exoplanets using interferometry,while CHES mission expects to discover habitable exoplanets orbiting FGK stars within 10 pc through astrometry.The above-mentioned missions are positively to achieve breakthroughs in the field of planetary science.
基金supported by the National Natural Science Foundation of China(Grant Nos. 10973044 and 10833001)the Natural Science Foundation of Jiangsu Provincethe Foundation of Minor Planets of Purple Mountain Observatory
文摘We model the interior of Europa using a method by which we set three layers of Europa and the composition of each layer in advance. Comparing the calculated mass and radius related to each model with the data derived by the observations, we propose three possible internal structure models for Europa. All models are assumed to be differentiated into a metallic core, a (Mg,Fe)2SiO4 silicate mantle and an outer water shell. The only difference amongst these models are the composition of the core. The core of Model I is composed of Fe, while Model II composed of FeS, and the two models are based on the inferences provided by Europa's external gravitational field. Model III has a core which consists of Fe-FeS alloy, similar to that of Earth's outer core. Model I has a Fe core with a radius of 431 km, a (Mg,Fe)2SiO4 mantle with 999 km and a water shell with 132 km. Model II has a 777 km FeS core, a 619 km (Mg,Fe)2SiO4 mantle and a 167 km water shell. Model III has a 571 km Fe0.8(FeS)0.2 core, a 832 km (Mg,Fe)2SiO4 mantle and a 166 km water shell. In all three models, the density range and the radius of each layer is consistent with those deduced by Anderson et al.
基金supported by the National Natural Science Foundation of China (Grant No.10973044,10833001)the Natural Science Foundation of Jiangsu Province(Grant No.BK20093411)the Foundation of Minor Planets of the Purple Mountain Observatory
文摘We perform numerical simulations to investigate tidal evolution of two single-planet systems,that is,WASP-50 and GJ 1214 and a two-planet system CoRoT-7.The results of orbital evolution show that tidal decay and circularization may play a significant role in shaping their final orbits,which is related to the initial orbital data in the simulations.For GJ 1214 system,different cases of initial eccentricity are also considered as only an upper limit of its eccentricity(0.27) is shown,and the outcome suggests a possible maximum initial eccentricity(0.4) in the adopted dynamical model.Moreover,additional runs with alternative values of dissipation factor Q1 are carried out to explore tidal evolution for GJ 1214b,and these results further indicate that the real Q1 of GJ 1214b may be much larger than its typical value,which may reasonably suggest that GJ 1214b bears a present-day larger eccentricity,undergoing tidal circularization at a slow rate.For the CoRoT-7 system,tidal forces make two planets migrating towards their host star as well as producing tidal circularization,and in this process tidal effects and mutual gravitational interactions are coupled with each other.Various scenarios of the initial eccentricity of the outer planet have also been done to investigate final planetary configuration.Tidal decay arising from stellar tides may still work for each system as the eccentricity decreases to zero,and this is in association with the remaining lifetime of each planet used to predict its future.
