Related papers: The lonely Moon, double asteroids, and multiple co…
Close, compact, hierarchical, multiple stellar systems, i.e., multiples having an outer orbital period from months to a few years, comprise a small, but continuously growing group of the triple and multiple star zoo. Many of them consist of…
When we are fortunate enough to view an exoplanetary system nearly edge-on, the star and planet periodically eclipse each other. Observations of eclipses (transits and occultations) provide a bonanza of information that cannot be obtained…
The lunar geological record is expected to contain a rich record of the galactic environment of the Solar System, including records of nearby (i.e. less than a few tens of parsecs) supernova explosions. This record will be composed of two…
Binary interactions are commonplace among massive stars, giving rise observed phenomena such as X-ray binaries, stripped stars & supernovae, and gravitational-wave sources. The multiplicity properties of massive stars thus represent a…
We know that giant planets played a crucial role in the making of our Solar System. The discovery of giant planets orbiting other stars is a formidable opportunity to learn more about these objects, what is their composition, how various…
Meteorites are a remarkable resource. They capture the imagination of people worldwide with their spectacular entry through Earth's atmosphere as fireballs, and their exotic character of being pieces of other worlds. Scientifically, they…
A time-dependent model of space-time is used to suggest simple explanations for the increasing of the Astronomical unit, as well as the increasing of the distance from the Earth to the Moon. The Pioneer anomaly is also considered.
This is a pedagogical review of recent results on the interactions of central massive black holes with stars very near them, focused on the black hole in the center of the Milky Way. Table of contents: [1] Introduction [2] Stellar dynamics…
The fates of planetary systems provide unassailable insights into their formation and represent rich cross-disciplinary dynamical laboratories. Mounting observations of post-main-sequence planetary systems necessitate a complementary level…
In this review presented at the Royal Society meeting, "Cometary Science After Rosetta", I present an overview of studies of small solar system objects that exhibit properties of both asteroids and comets (with a focus on so-called active…
Understanding the Moon's formation mechanism is necessary for studying not only the Moon itself, but also the evolution, formation, habitability, and structure of other planets and the moons in the Solar system and in extrasolar planetary…
Essentially everything of astronomical interest is either part of a galaxy, or from a galaxy, or otherwise relevant to the origin or evolution of galaxies. Diverse examples are that the isotropic composition of meteorites provides clues to…
Most stars are formed in a cluster or association, where the number density of stars can be high. This means that a large fraction of initially-single stars will undergo close encounters with other stars and/or exchange into binaries. We…
The Earth-Moon system is suggested to have formed through a single giant collision, in which the Moon accreted from the impact-generated debris disk. However, such giant impacts are rare, and during its evolution the Earth experienced many…
It is shown that the description of the solar cycle that takes into account the odd zonal harmonic of the solar magnetic field allows us to deepen our knowledge of two important aspects of the solar activity. First, to clarify and expand…
A combination of ground-based and spacecraft observations has uncovered two black holes of 10 billion solar masses in the nearby Universe. The finding sheds light on how these cosmic monsters co-evolve with galaxies.
In this review, three major changes in our understanding of the early history of the Solar System are presented. 1) Early differentiation: A few recent results support the idea that protoplanet formation and differentiation occurred partly…
We describe how cosmology has converged towards a beautiful model of the Universe: the Big Bang Universe. We praise this model, but show there is a dark side to it. This dark side is usually called ``the cosmological problems'': a set of…
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…
During the last stages of the terrestrial planet formation, planets grow mainly through giant-impacts with large planetary embryos. The Earth's Moon was suggested to form through one of these impacts. However, since the proto-Earth has…