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Of the few thousand discovered exoplanets, a significant number orbit in the habitable zone of their star. Many of them are gas giants lacking a rocky surface and solid water reservoirs necessary for life as we know it. The search for habitable environments may extend to the moons of these giant planets. No confirmed exomoon discoveries have been made as of today, but promising candidates are known. Theories suggest that moon formation is a natural process in planetary systems. We aim to study moon formation around giant planets in a phase similar to the final assembly of planet formation. We search for conditions for forming the largest moons with the highest possibility in circumplanetary disks, and investigate whether the resulting moons can be habitable. We determined the fraction of the circumplanetary disk's mass converted into moons using numerical N-body simulations where moon embryos grow via embryo-satellitesimal collisions, investigated in disks around giant planets consisting of 100 fully interacting embryos and 1000 satellitesimals. In fiducial simulations, a 10 Jupiter-mass planet orbited a solar analog star at distances of 1-5 au. To determine the habitability of the

"Moon-magnetosphere interaction" stands for the interaction of magnetospheric plasma with an orbiting moon. Observations and modeling of moon-magnetosphere interaction is a highly interesting area of space physics because it helps to better understand the basic physics of plasma flows in the universe and it provides geophysical information about the interior of the moons. Moon-magnetosphere interaction is caused by the flow of magnetospheric plasma relative to the orbital motions of the moons. The relative velocity is usually slower than the Alfvén velocity of the plasma around the moons. Thus the interaction generally forms Alfvén wings instead of bow shocks in front of the moons. The local interaction, i.e., the interaction within several moon radii, is controlled by properties of the atmospheres, ionospheres, surfaces, nearby dust-populations, the interiors of the moons as well as the properties of the magnetospheric plasma around the moons. The far-field interaction, i.e., the interaction further away than a few moon radii, is dominated by the magnetospheric plasma and the fields, but it still carries information about the properties of the moons. In this chapter we review the

Similarities in the non-mass dependent isotopic composition of refractory elements with the bulk silicate Earth suggest that both the Earth and the Moon formed from the same material reservoir. On the other hand, the Moon's volatile depletion and isotopic composition of moderately volatile elements points to a global devolatilization processes, most likely during a magma ocean phase of the Moon. Here, we investigate the devolatilisation of the molten Moon due to a tidally-assisted hydrodynamic escape with a focus on the dynamics of the evaporated gas. Unlike the 1D steady-state approach of Charnoz et al. (2021), we use 2D time-dependent hydrodynamic simulations carried out with the FARGOCA code modified to take into account the magma ocean as a gas source. Near the Earth's Roche limit, where the proto-Moon likely formed, evaporated gases from the lunar magma ocean form a circum-Earth disk of volatiles, with less than 30% of material being re-accreted by the Moon. We find that the measured depletion of K and Na on the Moon can be achieved if the lunar magma-ocean had a surface temperature of about 1800-2000 K. After about 1000 years, a thermal boundary layer or a flotation crust for

The paper addresses the possibility of a young Mars having had a massive moon, which synchronised the rotation of Mars, and gave Mars an initial asymmetric triaxiality to be later boosted by geological processes. It turns out that a moon of less than a third of the lunar mass was capable of producing a sufficient initial triaxiality. The asymmetry of the initial tidal shape of the equator depends on timing: the initial asymmetry is much stronger if the synchronous moon shows up already at the magma-ocean stage. From the moment of synchronisation of Mars' rotation with the moon's orbital motion, and until the moon was eliminated (as one possibility, by an impact in the beginning of the LHB), the moon was sustaining an early value of Mars' rotation rate.

The moon, moonlight, phases of the moon and its relatively simple recurring cycle has been of interest since time immemorial to the human beings, navigators, astronomers and astrologers. The fact that its orbit is elliptical as well its plane is inclined with the plane of rotation of the earth gives rise to new moon to full moon and solar and lunar eclipses. During the phase of the full moon, the luminous flux and its apparent size will depend on its distance from the earth. In case it is at farthest point known as lunar apogee causes smallest full moon or micro full moon and if it is closest to us termed as lunar perigee will result in macro full moon, also known as super moon, a term coined by astrologer Richard Nolle in 1979. The theoretical expressions for the lunar luminous fluxes on the earth representing the power of lunar light the earth intercepts in the direction normal to the incidence over an area of one square meter are derived for two extreme positions lunar apogee and lunar perigee. The expressions for the apparent sizes of full moons corresponding to said positions are also mentioned. It is found that full perigee moon is about 29 percent brighter and 14 percent big

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 systems. In this paper, I suggest a mechanism of the Moon formation. I posit that the Moon came into existence from the same gaseous cloud that the Earth originated from. The paper concludes that the moons can only form at the time of planet formation in a parallel and simultaneous process, and the new moons cannot form in a grown up Solar system. The Earth-Moon system is not a special exception in nature; rather it evolved following the same laws that other planets or moons have evolved from. This perspective successfully elucidates what happened between the disk formation and the accumulation of the Moon from the disk.

Almost all the planets of our solar system have moons. Each planetary system has however unique characteristics. The Martian system has not one single big moon like the Earth, not tens of moons of various sizes like for the giant planets, but two small moons: Phobos and Deimos. How did form such a system? This question is still being investigated on the basis of the Earth-based and space-borne observations of the Martian moons and of the more modern theories proposed to account for the formation of other moon systems. The most recent scenario of formation of the Martian moons relies on a giant impact occurring at early Mars history and having also formed the so-called hemispheric crustal dichotomy. This scenario accounts for the current orbits of both moons unlike the scenario of capture of small size asteroids. It also predicts a composition of disk material as a mixture of Mars and impactor materials that is in agreement with remote sensing observations of both moon surfaces, which suggests a composition different from Mars. The composition of the Martian moons is however unclear, given the ambiguity on the interpretation of the remote sensing observations. The study of the forma

Lunar hematite is formed by the oxidation of iron on the surface of the Moon by oxygen from the Earth's upper atmosphere. The Moon's surface is continuously affected by solar particles from the sun. However, Earth's magnetic tail blocks 99 % of the solar wind and provides windows of opportunity to transport oxygen from Earth's upper atmosphere to the Moon through magnetotail when it is in its full moon phase. Here, we propose to place a space weather observatory at the Earth-Moon L1 Lagrange point carrying a crucial payload onboard to study how Earth's magnetotail causes the Moon's surface to rust. The space weather observatory monitors the effect of Earth's magnetic field on the Moon using advanced spectroscopic sensors from Lagrange-based stations. Earth-moon L1 Lagrange point is the key location for space-weather observation as spacecraft near this point obtains a nearly unobstructed view of the moon. Numerical methods needed for a high-order analytical approximation have been implemented for more accurate predictions.

Exoplanets with and without a magnetic field are predicted to form, behave, and evolve very differently. Therefore, there is great need to directly constrain these fields to holistically understand the properties of exoplanets including their potential habitability. This goal aligns with the Astro2020 Decadal Survey recommendations. Observing planetary auroral radio emissions is among the most promising detection methods, but decades of searching have yet to yield a conclusive detection, though promising hints are now emerging from ground-based radio telescopes. However, these ground-based efforts are fundamentally limited by Earth's ionosphere, which blocks the low-frequency signals (<10 MHz) expected from terrestrial and Neptune-like exoplanets. In this white paper, we outline a strategy to overcome this barrier by utilizing the unique environment of the Moon. We discuss how the upcoming LuSEE-Night and ROLSES pathfinder missions will study our Solar System's planets as exoplanet analogs and place the first meaningful upper limits on exoplanetary radio flux below 10 MHz. Furthermore, we explore the revolutionary potential of the proposed future lunar arrays FarView and FARSIDE

The role of the moon in triggering earthquakes has been studied since the early 1900s. Theory states that as land tides swept by the moon cross fault lines, stress in the Earth's plates intensifies, increasing the likelihood of small earthquakes. This paper studied the association of the moon and sun with larger magnitude earthquakes (magnitude 5 and greater) using a worldwide dataset from the USGS. Initially, the positions of the moon and sun were considered separately. The moon showed a reduction of 1.74% (95% confidence) in earthquakes when it was 10 hours behind a longitude on earth and a 1.62% increase when it was 6 hours behind. The sun revealed even weaker associations (<1%). Binning the data in 6 hours quadrants (matching natural tide cycles) reduced the associations further. However, combinations of moon-sun positions displayed significant associations. Cycling the moon and sun in all possible quadrant permutations showed a decrease in earthquakes when they were paired together on the East and West horizons of an earthquake longitude (4.57% and 2.31% reductions). When the moon and sun were on opposite sides of a longitude, there was often a small (about 1%) increase in

We present another explanation for the moon illusion, the phenomenon in which the moon looks larger near the horizon than near the zenith. In our model of the moon illusion, the sky is considered a spatially-contiguous and geometrically-smooth surface. When an object such as the moon breaks the contiguity of the surface, instead of perceiving the object as appearing through a hole in the surface, humans perceive an occlusion of the surface. Binocular vision dictates that the moon is distant, but this perception model contradicts our binocular vision, dictating that the moon is closer than the sky. To resolve the contradiction, the brain distorts the projections of the moon to increase the binocular disparity, which results in an increase in the perceived size of the moon. The degree of distortion depends upon the apparent distance to the sky, which is influenced by the surrounding objects and the condition of the sky. As the apparent distance to the sky decreases, the illusion becomes stronger. At the horizon, apparent distance to the sky is minimal, whereas at the zenith, few distance cues are present, causing difficulty with distance estimation and weakening the illusion.

A new technique has been devised for the analysis of extensive air shower data in observing the effect of the moon on this data. In this technique the number of EAS events with arrival directions falling in error circles centered about the moving moon is compared to the mean number of events falling in error circles with centers randomly chosen in the sky. For any assumed angular radius of the error circle the deficit in EAS event count in the direction of moon i.e., Nsky-Nmoon which is a moon-related effect is interpreted as the shadow of the moon. A simple theoretical model has been developed to relate Nsky to the angular radius of the error circle and has been applied to the counts from the moon's direction in order to extract the physical parameters of the shadow of the moon. The technique and the theoretical model has been used on 1.7 *10^5 EAS events recorded at Alborz observatory.

This article investigates long-term orbits within the Earth's magnetosphere, specifically focusing on orbits where the argument of periapsis is synchronized with changes induced by lunar gravity assists and the Earth's argument of latitude over a complete orbital period in Earth-Moon resonance. In the Earth-Moon rotating frame, resonance orbits appear repetitive; however, the argument of periapsis shifts due to the third-body effects from lunar flybys. The extent of this shift is influenced by the Jacobi integral associated with the resonance orbit. To identify feasible resonance orbits and the optimal Jacobi integral, we map the argument of periapsis change against the Jacobi integral for each prospective orbit. This synchronization allows the spacecraft to remain within a confined region in space when observed from the Sun-Earth rotating frame. Finally, the article discusses the applications of these long-term Earth magnetosphere science orbits, including orbit-orientation reconfiguration (station keeping) and stability.

The hypothesis of lunar origin by a single giant impact can explain some aspects of the Earth-Moon system. However, it is difficult to reconcile giant impact models with the compositional similarity of the Earth and Moon without violating angular momentum constraints. Furthermore, successful giant impact scenarios require very specific conditions such that they have a low probability of occurring. Here we present numerical simulations suggesting that the Moon could instead be the product of a succession of a variety of smaller collisions. In this scenario, each collision forms a debris disk around the proto-Earth that then accretes to form a moonlet. The moonlets tidally advance outward, and may coalesce to form the Moon. We find that sub-lunar moonlets are a common result of impacts expected onto the proto-Earth in the early solar system and find that the planetary rotation is limited by impact angular momentum drain. We conclude that, assuming efficient merger of moonlets, a multiple impact scenario can account for the formation of the Earth-Moon system with its present properties.

The detection of the New Moon at sunset is of importance to communities based on the lunar calendar. This is traditionally undertaken with visual observations. We propose a radio method which allows a higher visibility of the Moon relative to the Sun and consequently gives us the ability to detect the Moon much closer to the Sun than is the case of visual observation. We first compare the relative brightness of the Moon and Sun over a range of possible frequencies and find the range 5--100\,GHz to be suitable. The next consideration is the atmospheric absorption/emission due to water vapour and oxygen as a function of frequency. This is particularly important since the relevant observations are near the horizon. We show that a frequency of $\sim 10$ GHz is optimal for this programme. We have designed and constructed a telescope with a FWHM resolution of 0$^\circ{}\!\!$.6 and low sidelobes to demonstrate the potential of this approach. At the time of the 21 May 2012 New Moon the Sun/Moon brightness temperature ratio was $72.7 \pm 2.2$ in agreement with predictions from the literature when combined with the observed sunspot numbers for the day. The Moon would have been readily detect

The Giant Impact is currently accepted as the leading theory for the formation of Earth's Moon. Successful scenarios for lunar origin should be able to explain the chemical composition of the Moon (volatile content and stable isotope ratios), the Moon's initial thermal state, and the system's bulk physical and dynamical properties. Hydrocode simulations of the formation of the Moon have long been able to match the bulk properties, but recent, more detailed work on the evolution of the protolunar disk has yielded great insight into the origin of the Moon's chemistry, and its early thermal history. Here, I show that the community has constructed the elements of an end-to-end theory for lunar origin that matches the overwhelming majority of observational constraints. In spite of the great progress made in recent years, new samples of the Moon, clarification of processes in the impact-generated disk, and a broader exploration of impact parameter space could yield even more insights into this fundamental and uniquely challenging geophysical problem.

The Earth-Moon system is unusual in several respects. The Moon is roughly 1/4 the radius of the Earth - a larger satellite-to-planet size ratio than all known satellites other than Pluto's Charon. The Moon has a tiny core, perhaps with only ~1% of its mass, in contrast to Earth whose core contains nearly 30% of its mass. The Earth-Moon system has a high total angular momentum, implying a rapidly spinning Earth when the Moon formed. In addition, the early Moon was hot and at least partially molten with a deep magma ocean. Identification of a model for lunar origin that can satisfactorily explain all of these features has been the focus of decades of research.

For centuries some scientists have argued that there is activity on the Moon (or water, as recounted in Parts I & II), while others have thought the Moon is simply a dead, inactive world. The question comes in several forms: is there a detectable atmosphere? Does the surface of the Moon change? What causes interior seismic activity? From a more modern viewpoint, we now know that as much carbon monoxide as water was excavated during the LCROSS impact, as detailed in Part I, and a comparable amount of other volatiles were found. At one time the Moon outgassed prodigious amounts of water and hydrogen in volcanic fire fountains, but released similar amounts of volatile sulfur (or SO2), and presumably large amounts of carbon dioxide or monoxide, if theory is to be believed. So water on the Moon is associated with other gases. We review what is known (and touch on what is unknown) about outgassing of various gases from the Moon.

In the framework of the planar CR3BP for mass parameter mu=0.0121505, corresponding to the Earth-Moon system, we identify and describe 80 families of periodic orbits encircling both the Earth and the Moon ("transfer" orbits). All the orbits in these families have very low energies, most of them corresponding to values of the Jacobi constant C for which the Hill surface is closed at the Lagrangian point L2. All of these orbits have also short period T, generally under six months. Most of the families are composed of orbits that are asymmetric with respect to the Earth-Moon axis. The main results presented for each family are: (i) the characteristic curves T(h), y(h), v_y(h), and v_x(h) on the Poincare section Sigma_1={x=0.836915310,y,v_x>0,v_y} normal to the Earth-Moon axis at the Lagrangian point L1, parameterized by their energy h=-C/2 in the synodic coordinate system; (ii) the stability parameter along each family; (iii) the intersections x_i(h) of the orbits with the Earth-Moon axis, on the Poincare section Sigma_2={x,y=0,v_x},v_y>0}; (iv) plots of some selected orbits and details of their circumlunar region; and (v) numerical data for the intersection of an orbit with Sig