相关论文: Hydrocode modeling of the spallation process durin…
We model large-scale ($\approx$2000km) impacts on a Mars-like planet using a Smoothed Particle Hydrodynamics code. The effects of material strength and of using different Equations of State on the post-impact material and temperature…
High-speed impact ejecta at velocities comparable to the impact velocity are expected to contribute to material transport between planetary bodies and deposition of ejecta far from the impact crater. We investigated the behavior of…
The precipitation of energetic neutral atoms, produced through charge exchange collisions between solar wind ions and thermal atmospheric gases, is investigated for the Martian atmosphere. Connections between parameters of precipitating…
Shock-physics numerical codes are essential tools for describing the short but extreme fragmentation stage of the hypervelocity impact process on asteroids. However, accurately representing complex interior structures, surfaces, and contact…
We have examined the fate of impact ejecta liberated from the surface of Mercury due to impacts by comets or asteroids, in order to study (1) meteorite transfer to Earth, and (2) re-accumulation of an expelled mantle in giant-impact…
Numerous small bodies inevitably lead to cratering impacts on large planetary bodies during planet formation and evolution. As a consequence of these small impacts, a fraction of the target material escapes from the gravity of the large…
Our earlier laboratory measurements showed that low-velocity sand impacts release fine <5 {\mu}m dust from a Martian simulant soil. This dust will become airborne in the Martian atmosphere. Here, we extend this study by measuring…
Potential microbial contamination of Martian moons, Phobos and Deimos, which can be brought about by transportation of Mars ejecta produced by meteoroid impacts on the Martian surface, has been comprehensively assessed in a statistical…
Within the RoadMap project we investigated the microphysical aspects of particle collisions during saltation on the Martian surface in laboratory experiments. Following the size distribution of ejected particles, their aerodynamic…
Collisions between hot hydrogen atoms and CO$_2$ play a central role in energy transfer and atmospheric escape in CO$_2$-rich planetary atmospheres. We present quantum mechanical $j_z$-conserving coupled-states calculations of…
In our solar system, Mars-sized protoplanets frequently collided with each other during the last stage of terrestrial planet formation called the giant impact stage. Giant impacts eject a large amount of material from the colliding…
Dry lakebeds might constitute large volatile reservoirs on Mars. Hypervelocity impacts onto ancient dry lakebeds would have affected the volatile distribution on Mars. We developed a new experimental method to investigate the response of…
We investigate the influence of impacts of large planetesimals and small planetary embryos on the early Martian surface on the hydrodynamic escape of an early steam atmosphere that is exposed to the high soft X-ray and EUV flux of the young…
Collisions between large, similar-sized bodies are believed to shape the final characteristics and composition of terrestrial planets. Their inventories of volatiles such as water, are either delivered or at least significantly modified by…
Neutron star mergers (NSMs) are rapid neutron capture ($\textit{r}$-process) nucleosynthesis sites that expel matter at high velocities, from $0.1c$ to as high as $0.6c$. Nuclei ejected at these speeds are sufficiently energetic to initiate…
The evolution of the orbits of bodies ejected from the Earth, Moon, Mercury and Mars was studied. At ejection velocities about 12-14 km/s, the fraction of bodies ejected from the Earth that fall back onto the Earth was about 0.15-0.25. The…
We present a detailed theoretical analysis of a non-thermal escape of molecular hydrogen from Mars induced by collisions with hot atomic oxygen from martian corona. To accurately describe the energy transfer in O + H$_2(v,j)$ collisions, we…
This work is a theoretical study of the speed at which the material of an impacted target is ejected during the formation of an impact crater. Our model, starting from the first principle of thermodynamics, can describes the speed of the…
It has been suggested that the ejection to interplanetary space of terrestrial crustal material, accelerated in a large impact, may result in the interchange of biological material between Earth and other Solar System bodies. In this paper,…
Aeolian sediment transport is observed to occur on Mars as well as other extraterrestrial environments, generating ripples and dunes as on Earth. The search for terrestrial analogues of planetary bedforms, as well as environmental…