相关论文: The hazard from fragmenting comets

A large sample of planet-planet scattering events for three planet systems with different orbital separations and masses is analyzed with a multiple regression model. The dependence of the time for the onset of instability on the masses of…

A variety of phenomena connected with the formation of a dinuclear complex is observed in the heavy ion collisions at low energies. The dinuclear system model allows us to analyze the experimental data and to interpret them by comparison of…

Periodic comets of different dynamical groups with orbits at 2 - 5 AU still occasionally active. The observed dust activity of such objects can be connected with processes of water ice sublimation (MBCs) or crystallization of amorphous…

The complete sample of large-perihelion nearly-parabolic comets discovered during the period 1901-2010 is studied starting from their orbit determination. Next, an orbital evolution that includes three perihelion passages…

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…

We carry out a comprehensive study of supernova ejecta-companion interaction in massive binary systems. We aim to physically understand the kinematics of the interaction and predict observational signatures. To do this we perform…

The study of colliding galaxies has progressed rapidly in the last few years, driven by observations with powerful new ground and space-based instruments. These instruments have used for detailed studies of specific nearby systems,…

So-called 'dark comets' are small, morphologically inactive near-Earth objects (NEOs) that exhibit nongravitational accelerations inconsistent with radiative effects. These objects exhibit short rotational periods (minutes to hours), where…

Following the suggestion of Black (1997) that some massive extrasolar planets may be associated with the tail of the distribution of stellar companions, we investigate a scenario in which 5 < N < 100 planetary mass objects are assumed to…

In granular systems, thermal cycling causes compaction, creep, penetration of dense objects, and ratcheting of grains against each other. On asteroid surfaces, thermal cycling is high amplitude and can happen billions of times in a few…

Planetary systems formed in clusters may be subject to stellar encounter flybys. Here we create a diverse range of representative planetary systems with different orbital scales and planets' masses and examine encounters between them in a…

The merging rate of cosmic structures is computed, relying on the Ansatz that they can be predicted in the initial linear density field from the coalescence of critical points with increasing smoothing scale, used here as a proxy for cosmic…

The solar system's dynamical state can be explained by an orbital instability among the giant planets. A recent model has proposed that the giant planet instability happened during terrestrial planet formation. This scenario has been shown…

On 2013 November 28 Comet ISON (C/2012 S1) will pass by the Sun with a perihelion distance of 2.7 solar radii. Understanding the possible outcomes for the comet's response to such a close passage by the Sun is important for planning…

Intrinsically faint comets in nearly-parabolic orbits with perihelion distances much smaller than 1 AU exhibit strong propensity for suddenly disintegrating at a time not long before perihelion, as shown by Bortle (1991). Evidence from…

The current properties of small bodies provide important clues to their origin and history. However, how much small bodies were processed by past collisions and to what extent they retain a record of processes that took place during the…

We hypothesise that planets are made by tidal downsizing of migrating giant planet embryos. The proposed scheme for planet formation consists of these steps: (i) a massive young protoplanetary disc fragments at R ~ several tens to hundreds…

Space debris larger than 1 cm can damage space instruments and impact Earth. The low-Earth orbits (at heights smaller than 2000 km) and orbits near the geostationary- Earth orbit (at 35786 km height) are especially endangered, because most…

When the EPOXI spacecraft flew by Comet 103P/Hartley 2, it observed large particles floating around the comet nucleus. These particles are likely low-density, centimeter- to decimeter-sized clumps of ice and dust. While the origin of these…

All planets and satellites of our solar system are subject to a continuous rain of material, ranging in size from specks of dust to objects the size of boulders. Upon impact, these objects deposit their kinetic energy into the incident…