Related papers: Impact cratering and the Oort cloud
Given rapid photodissociation and photodegradation, the recently discovered organics in the Martian subsurface and atmosphere were probably delivered in geologically recent times. Possible parent bodies are C-type asteroids, comets, and…
A massive black hole (MBH) in a galactic center drives a flow of stars into nearly radial orbits to replace those it destroyed. Stars whose orbits cross the event horizon r_s or the tidal disruption radius r_t are promptly destroyed in an…
The tidal field of galaxies is known generally to be disruptive. However, in the case of galaxy mergers, a compressive mode of tidal wave may develop and last long enough to cocoon the formation of star clusters. Using an N-body simulation…
A large fraction of stars are formed in dense clusters. In the cluster, close encounters between stars at distances less than 100 au are common. It has been shown that during close encounters planets can transfer between stars. Such…
Like many airless planetary surfaces, the surface of the Moon is scattered by populations of blocks and smaller boulders. These features decrease in abundance with increasing exposure time due to comminution by impact bombardment and…
We estimated the rate of comet and asteroid collisions with the terrestrial planets by calculating the orbits of 13000 Jupiter-crossing objects (JCOs) and 1300 resonant asteroids and computing the probabilities of collisions based on…
Outbursts due to dramatic increases in the mass accretion rate are the most extreme type of variability in young stellar objects. We searched for outbursts among 319 protostars in the Orion molecular clouds by comparing 3.6, 4.5, and 24…
Cosmic rays (CR), both solar and Galactic, have an ionising effect on the Earth's atmosphere and are thought to be important for prebiotic molecule production. In particular, the $\rm{H_2}$-dominated atmosphere following an ocean-vaporising…
Gamma-Ray Bursts (GRBs) are likely to have made a number of significant impacts on the Earth during the last billion years. We have used a two-dimensional atmospheric model to investigate the effects on the Earth's atmosphere of GRBs…
The orbital regime of a terrestrial planet plays a significant role in shaping its atmospheric dynamics, climate, and hence potential habitability. The orbit is also likely to play a role in shaping the response of a planetary atmosphere to…
Scattering of particles in the gravitational field of rotating black holes is considered. Expressions for scattering energy of particles in the centre of mass system are obtained. It is shown that scattering energy of particles in the…
(Abridged) The propagation of ionizing radiation through model atmospheres of terrestrial-like exoplanets is studied for a large range of column densities and incident photon energies using a Monte Carlo code we have developed to treat…
Reconstructions of the paleoclimate indicate that ancient climatic fluctuations on Earth are often correlated with variations in its orbital elements. However, the chaos inherent in the solar system's orbital evolution prevents numerical…
In most extrasolar planetary systems, the present orbits of known giant planets admit the existence of stable terrestrial planets. Those same giant planets, however, have typically eccentric orbits that hint at violent early dynamics less…
The role of feedback from massive stars is believed to be a key element in the evolution of molecular clouds. We use high-resolution 3D SPH simulations to explore the dynamical effects of a single O7 star located at the centre of a…
Model Production Function chronology uses dynamic models of the Main Belt Asteroids (MBAs) and Near Earth Objects (NEOs) to derive the impactor flux to a target body. This is converted into the crater size-frequency-distribution for a…
Metallic bodies that were the cores of differentiated bodies are sources of iron meteorites and are considered to have formed early in the terrestrial planet region before migrating to the main asteroid belt. Surface temperatures and mutual…
Micrometeoroids (cosmic dust with size between a few $\mu$m and $\sim$1 mm) dominate the annual extraterrestrial mass flux to the Earth. We investigate the range of physical processes occurring when micrometeoroids traverse the atmosphere.…
The orbital evolution of Jupiter-family comets (JFCs), resonant asteroids, and asteroidal, trans-Neptunian, and cometary dust particles under the gravitational influence of planets was integrated. For dust particles we also considered…
Planets between 1-4 Earth radii with orbital periods <100 days are strikingly common. The migration model proposes that super-Earths migrate inwards and pile up at the disk inner edge in chains of mean motion resonances. After gas disk…