Related papers: Comet and Asteroid Hazard to the Terrestrial Plane…
We present an improved estimate of the occurrence rate of small planets orbiting small stars by searching the full four-year Kepler data set for transiting planets using our own planet detection pipeline and conducting transit injection and…
We provide a fast method for computing constraints on impactor pre-impact orbits, applying this to the late giant impacts in the Solar System. These constraints can be used to make quick, broad comparisons of different collision scenarios,…
We investigated the probability that an inelastic collision of planetesimals within the Hill sphere of the Jovian planets could explain the presence and orbits of observed irregular satellites. Capture of these satellites via this mechanism…
A new classification scheme is introduced for comet-like bodies in the Solar system. It covers the traditional comets as well as the Centaurs and Edgeworth-Kuiper belt objects. At low inclinations, close encounters with planets often result…
We observed 34 comets using the 24 micron camera on the Spitzer Space Telescope. Each image contains the nucleus and covers at least 10^6 km of each comet's orbit. Debris trails due to mm-sized or larger particles were found along the…
A planet orbiting in a disk of planetesimals can experience an instability in which it migrates to smaller orbital radii. Resonant interactions between the planet and planetesimals remove angular momentum from the planetesimals, increasing…
It is well known that planets with radii between that of Earth and Neptune have been the most commonly detected to-date. To classify these planets as either terrestrial or gaseous, typically we turn to mass-radius relations and composition…
Stars which pass close to the Sun can perturb the Oort cloud, injecting comets into the inner solar system where they may collide with the Earth. Using van Leeuwen's re-reduction of the Hipparcos data complemented by the original Hipparcos…
Comet 3I/ATLAS, also known as C/2025 N1, was discovered on 2025 July 1 UT by NASA Asteroid Terrestrial-impact Last Alert System (ATLAS), with a v$_{\infty}$ $\sim$ 58 kms$^{-1}$. This is the fastest among the three interstellar objects…
We discuss a hypothetical existential threat from a 10 km diameter bolide discovered 6 months prior to impact with one case being a comet and the other being an asteroid. We show that an extension of our work on bolide fragmentation using…
The compositional and morphological evolution of minor bodies in the Solar System is primarily driven by the evolution of their heliocentric distances, as the level of incident solar radiation regulates cometary activity. We investigate the…
Significant numbers of free-floating planetary-mass objects have been discovered in nearby star-forming regions by the James Webb Space Telescope, including a substantial number (42) of Jupiter Mass Binary Objects ('JuMBOs') in the Orion…
Jupiter Trojan asteroids are located around L4 and L5 Lagrangian points on relatively stable orbits, in 1:1 MMR with Jupiter. However, not all of them lie in orbits that remain stable over the age of the Solar System. Unstable zones allow…
Planet formation theories predict a large but still undetected population of short-period terrestrial planets orbiting brown dwarfs. Should specimens of this population be discovered transiting relatively bright and nearby brown dwarfs, the…
Determining whether Earth-like planets are common or rare looms as a touchstone in the question of life in the universe. We searched for Earth-size planets that cross in front of their host stars by examining the brightness measurements of…
A numerical simulation of the Oort cloud is used to explain the observed orbital distributions and numbers of Jupiter-family and Halley-type short-period comets. Comets are given initial orbits with perihelion distances between 5 and 36 AU,…
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…
Recent observational missions have uncovered a significant number of compact multi-exoplanet systems. The tight orbital spacing of these systems has led to much effort being applied to the understanding of their stability; however, a key…
Both simulations and observations indicate that stars form in filamentary, hierarchically clustered associations, most of which disperse into their galactic field once feedback destroys their parent clouds. However, during their early…
The problem of origin and age of asteroid families is studied very intensively. First of all youngest families are interesting due to possibility of the reconstruction their collisional history. But in oldest families present objects with…