Related papers: Stone structures in the Syrian Desert
The formation of vegetation patterns in the arid and the semi-arid climatic zones is studied. Threshold for the biomass of the perennial flora is shown to be a relevant factor, leading to a frozen disordered patterns in the arid zone. In…
Saturn's rings, reminiscent of an early Solar System present a unique opportunity to investigate experimentally some mechanisms thought to be responsible for planet and planetesimal formation in protoplanetary discs. Here we extended the…
It is shown that in a classical spacetime with multiply connected space slices having the topology of a torus, closed timelike curves are also formed. We call these spacetime ringholes. Two regions on the torus surface can be distinguished…
The Hyades is the nearest open cluster, relatively young and containing numerous A-type stars; its known age, distance, and metallicity make it an ideal site to study planetary systems around 2-3 Msun stars at an epoch similar to the late…
Our investigation is motivated by the recent discovery of asteroids orbiting the Sun and simultaneously staying near one of the Solar System planets for a long time. This regime of motion is usually called the quasi-satellite regime, since…
The study of the structure of translational tilings has captivated mathematicians, scientists, and the general public for centuries and continues to thrive at the crossroads of analysis, combinatorics, dynamics, logic, number theory, and…
We discuss general aspects of non-relativistic quantum chaos theory of scattering of a quantum particle on a system of a large number of naked singularities. We define such a system space-temporal Sinai billiard We dis- cuss the problem in…
The Pluto system is an archetype for the multitude of icy dwarf planets and accompanying satellite systems that populate the vast volume of the solar system beyond Neptune. New Horizons' exploration of Pluto and its five moons gave us a…
Planetary rings are often speculated as being a relatively common attribute of giant planets, partly based on their prevalence within the Solar System. However, their formation and sustainability remain a topic of open discussion, and the…
The Earth is impacted by 35-40 metre-scale objects every year. These meteoroids are the low mass end of impactors that can do damage on the ground. Despite this they are very poorly surveyed and characterised, too infrequent for ground…
The discovery that the centaur (10199) Chariklo possesses a ring system opens questions about their origin. We here asses the plausibility of different scenarios for the origin of the observed ring system. We first consider the possibility…
In this paper we build models for short-term, mean-term and long-term dynamics of dune in desert. They are models that are degenerated parabolic equations which are, moreover, singularly perturbed. We, then give existence and uniqueness…
At sufficiently high pressures (~Mbar) and low temperatures (~1e3-1eK), hydrogen and helium become partly immiscible. Interpretations of Jupiter and Saturn's magnetic fields favor the existence of a statically stable layer near the Mbar…
On Mars, fields of sand dunes contrast with the general cratered, rocky terrain commonly seen from orbit. Near the equator, in Gale Crater, images from the rover, Curiosity, also reveal order on smaller scales: ripples on dunes, and ground…
We have made an extensive search for grouping amongst the near Earth asteroids (NEAs). We used two D- functions and rigorous cluster analysis approach. We have found sev- eral new groups (associations) among the NEAs: the objects moving on…
The spatial rock-paper-scissors ecosystem, where three species interact cyclically, is a model example of how spatial structure can maintain biodiversity. We here consider such a system for a broad range of interaction rates. When one…
We explore the spatial distribution of organics on Ceres using the visible and near-infrared data collected by the Dawn mission. We employ a spectral mixture analysis (SMA) approach to map organic materials within the Ernutet crater at the…
Old, digitized astronomical images taken before the human spacefaring age offer a unique view of the sky devoid of known artificial satellites. In this paper, we have carried out the first optical searches ever for non-terrestrial artifacts…
Within a fairly short amount of time, the Islamic State of Iraq and Syria (ISIS) has managed to put large swaths of land in Syria and Iraq under their control. To many observers, the sheer speed at which this "state" was established was…
The Chinese Pyramids are huge ancient burial mounds. In the satellite images we can see some complexes where the main buildings are the pyramidal mounds of an emperor and his empress. Here we discuss a possible sunrise/sunset orientation of…