Cycloids, arcuate features observed on Europa’s surface, have been interpreted as tensile cracks that form in response to diurnal tidal stress caused by Europa’s orbital eccentricity. Stress from non-synchronous rotation may also contribute to tidal stress, and its influence on cycloid shapes has been investigated as well. Obliquity, fast precession, and physical libration would contribute to t...

Mapping the orbital obliquity distribution of young planets is one avenue towards understanding mechanisms that sculpt architectures planetary systems. TOI-942 a field star, with an age ~60 Myr, hosting system consisting two transiting Neptune-sized in 4.3- and 10.1-day period orbits. We observed spectroscopic transits inner Neptune TOI-942b to determine its projected angle. Through partial tra...

Context. It is widely accepted that the large obliquity of Uranus is the result of a great tangential collision (GC) with an Earth size proto-planet at the end of the accretion process. The impulse imparted by the GC had affected the Uranian satellite system. Very recently, nine irregular satellites (irregulars) have been discovered around Uranus. Their orbital and physical properties, in parti...

Recovery Factor is an important parameter in determining commercial viability of the oil Reservoirs. Wettability is a major factor that affects oil Recovery. Therefore, changing rock wettability may enhance oil recovery. In this paper, the effect of polysilicon nanoparticles on wettability change of Iranian carbonate reservoir is investigated. To assess this, hydrophilic changes of carbonate ro...

Introduction The goal of posterior spinal fusion in neuromuscular scoliosis is to obtain a balanced trunk as well as accommodative, pressurefree seating on a level pelvis. Development of pelvic obliquity or involvement of the pelvis in the scoliotic curve can cause difficulties with seating, costopelvic impingement, and worsening pulmonary function, ultimately leading to difficulty with caregiv...

We analyze three-body decays of and . Under the factorization approach, there are tree level diagrams for these decay modes and the transition matrix element of decay is factorized into a form factor multiplied by decay constant and form factor multiplied into weak vertices form factor. The transition matrix element of decay is also factorized into a form factor multiplied into weak vertic...

We present a comprehensive theoretical study on the spin evolution of planet under combined effects tidal dissipation and gravitational perturbation from an external companion. Such "spin + companion" system (called Colombo's top) appears in many [exo]planetary contexts. The competition between torque (which drives spin-orbit alignment synchronization) companion orbital precession planet) gives...

The question of climate at high obliquity is raised in the context of both exoplanet studies (e.g. habitability) and paleoclimates studies (evidence for low-latitude glaciation during the Neoproterozoic and the ‘‘Snowball Earth’’ hypothesis). States of high obliquity, /, are distinctive in that, for / P 54!, the poles receive more solar radiation in the annual mean than the equator, opposite to...

Introduction: Since the discovery of ice in cold, permanently shadowed polar craters on Mercury[1], debate has reopened over the presence of ice in similar environments on the Moon. Though the Moon has similar shadowed craters currently, this has not always been the case. Here we examine a 4.5 billion year history of insolation in the lunar polar environment and the resulting surface and subsur...