Stagnant lid tectonics:Perspectives from silicate planets,dwarf planets, large moons,and large asteroids

To better understand Earth's present tectonic style-plate tectonics—and how it may have evolved from single plate(stagnant lid) tectonics, it is instructive to consider how common it is among similar bodies in the Solar System. Plate tectonics is a style of convection for an active planetoid where lid fragment(plate) motions reflect sinking of dense lithosphere in subduction zones, causing upwelling of asthenosphere at divergent plate boundaries and accompanied by focused upwellings, or mantle plumes;any other tectonic style is usefully called "stagnant lid" or "fragmented lid". In 2015 humanity completed a 50+ year effort to survey the 30 largest planets, asteroids, satellites, and inner Kuiper Belt objects,which we informally call "planetoids" and use especially images of these bodies to infer their tectonic activity. The four largest planetoids are enveloped in gas and ice(Jupiter, Saturn, Uranus, and Neptune)and are not considered. The other 26 planetoids range in mass over 5 orders of magnitude and in diameter over 2 orders of magnitude, from massive Earth down to tiny Proteus; these bodies also range widely in density, from 1000 to 5500 kg/m^3. A gap separates 8 silicate planetoids with ρ = 3000 kg/m^3 or greater from 20 icy planetoids(including the gaseous and icy giant planets) with ρ = 2200 kg/m^3 or less. We define the "Tectonic Activity Index"(TAI), scoring each body from 0 to 3 based on evidence for recent volcanism, deformation, and resurfacing(inferred from impact crater density). Nine planetoids with TAI = 2 or greater are interpreted to be tectonically and convectively active whereas 17 with TAI <2 are inferred to be tectonically dead. We further infer that active planetoids have lithospheres or icy shells overlying asthenosphere or water/weak ice. TAI of silicate(rocky) planetoids positively correlates with their inferred Rayleigh number. We conclude that some type of stagnant lid tectonics is the dominant mode of heat loss and that plate tectonics is unusual. To make progress understanding Earth's tectonic history and the tectonic style of active exoplanets, we need to better understand the range and controls of active stagnant lid tectonics.

Covariance analysis of periodic and quasi-periodic orbits around Phobos with applications to the Martian Moons eXploration mission

Understanding the internal composition of a celestial body is fundamental for formulating theories regarding its origin.Deep knowledge of the distribution of mass under the body’s crust can be achieved by analyzing its moments of inertia and gravity field.In this regard,the two moons of the Martian system have not yet been closely studied and continue to pose questions regarding their origin to the space community;thus,they deserve further characterization.The Martian Moons eXploration mission will be the first of its kind to sample and study Phobos over a prolonged period.This study aims to demonstrate that the adoption of periodic and quasi-periodic retrograde trajectories would be beneficial for the scientific value of the mission.Here,a covariance analysis was implemented to compare the estimation of high-order gravitational field coefficients from different orbital geometries and for different sets of processed observables.It was shown that the adoption of low-altitude non-planar quasi-satellite orbits would help to refine the knowledge of the moon’s libration angle and gravitational field.

The First Ground-based White Light Lunar Polarization Imaging:A New Kind of FeO Observation on the Near Side of the Moon

Lunar optical polarization is a fascinating phenomenon that occurs when sunlight reflects off the surface of the Moon and becomes polarized.This study employs a novel split-focus plane polarimetric camera to conduct the initial white light polarimetric observations on the near side of the Moon.We obtained the linear degree of polarization(DOP)parameters of white light by observation from the eastern and western hemispheres of the Moon.The findings indicate that the white light polarization is lower in the lunar highland than in the lunar maria overall.Combining the analysis of lunar soil samples,we noticed and determined that the DOP parameters of white light demonstrate high consistency with iron oxide on the Moon.This study may serve as a new diagnostic tool for the Moon.

Basic Survey Scheduling for the Wide Field Survey Telescope(WFST)

Aiming at improving the survey efficiency of the Wide Field Survey Telescope, we have developed a basic scheduling strategy that takes into account the telescope characteristics, observing conditions, and weather conditions at the Lenghu site. The sky area is divided into rectangular regions, referred to as “tiles,” with a size of2°. 577 × 2°. 634 slightly smaller than the focal area of the mosaic CCDs. These tiles are continuously filled in annulars parallel to the equator. The brightness of the sky background, which varies with the moon phase and distance from the moon, plays a significant role in determining the accessible survey fields. Approximately 50connected tiles are grouped into one block for observation. To optimize the survey schedule, we perform simulations by taking into account the length of exposures, data readout, telescope slewing, and all relevant observing conditions. We utilize the Greedy Algorithm for scheduling optimization. Additionally, we propose a dedicated dithering pattern to cover the gaps between CCDs and the four corners of the mosaic CCD array, which are located outside of the 3° field of view. This dithering pattern helps to achieve relatively uniform exposure maps for the final survey outputs.

Interrelationships between Length of the Day, Moon Distance, Phanerozoic Geodynamic Cycles, Tidal Dissipation and Earth’s Core: Review and Analysis

The rotation of the Earth and the related length of the day (LOD) are predominantly affected by tidal dissipation through the Moon and the growth of the Earth’s core. Due to the increased concentration of mass around the rotation axis of the spinning Earth during the growth of the core the rotation should have been accelerated. Controversially the tidal dissipation by the Moon, which is mainly dependent on the availability of open shallow seas and the kind of Moon escape from a nearby position, acts towards a deceleration of the rotating Earth. Measurements of LOD for Phanerozoic and Precambrian times open ways to solve questions concerning the geodynamical history of the Earth. These measurements encompass investigations of growth patterns in fossils and depositional patterns in sediments (Cyclostratigraphy, Tidalites, Stromatolites, Rhythmites). These patterns contain information on the LOD and on the changing distance between Earth and Moon and can be used as well for a discussion about the growth of the Earth’s core. By updating an older paper with its simple approach as well as incorporating newly published results provided by the geoscientific community, a moderate to fast growth of the core in a hot early Earth will be favored controversially to the assumption of a delayed development of the core in an originally cold Earth. Core development with acceleration of Earth’s rotation and the contemporaneous slowing down due to tidal dissipation during the filling of the ocean may significantly interrelate.

Earth: Review Article

Every year on 22 April, we have celebrated Earth Day and the beautiful planet we call home. Earth Day, established in 1970, has been used to highlight our planet’s environmental challenges and raise awareness of the importance of protecting our world for future generations [1]. To provide the protection of our planet, we should explain Earth’s environmental challenges to the best of our knowledge in frames of contemporary Geophysics. This paper gives a short overview of the developed Hypersphere World-Universe Model (WUM) and pay particular attention to the principal role of Dark Matter (DM) in the Earth’s life. In this manuscript, we discuss different aspects of the Earth: a condition of Young Earth before the Beginning of life on It;Internal Structure;“The 660-km Boundary” that we named Geomagma;Random Variations of Earth’s Rotational Speed on a daily basis;Origin of Moon;Expanding Earth;Internal Heating;Faint Young Sun paradox;Geocorona and Planetary Coronas;High-Energy Atmospheric Physics. WUM proposed principally different ways to solve the problems of Internal Heating, Origin of the Moon, and Faint Young Sun paradox based on DM core of the Earth. The Model revealed the fact that the Sun Activity causes the Geomagma Activity and, as a consequence, Random Variations of Earth’s Rotational Speed by the varying Sun’s magnetic field.

2024的祝福:《You Raise Me Up》

《You Raise Me Up》是一首来自于Secret Garden神秘园的著名歌曲,收录于他们2002年发行的专辑《Once In A Red Moon》中。Secret Garden神秘园组合是由爱尔兰女小提琴手Fionnuala Sherry菲奥诺拉·莎莉和挪威作曲家兼键盘手Rolf Lovland罗尔夫·劳弗兰组建的著名新世纪音乐风格乐队。

Delicious Mooncakes:中学英语词汇与表达实用教学法

引言1.1“Delicious Mooncakes”主题的选取背景与意义“Delicious Mooncakes”这一主题选取的背景是基于中秋节这一重要的中国传统节日,月饼作为中秋节的象征,蕴含着丰富的文化内涵和社会价值。通过这一主题,学生可以更加深入地了解中国的传统文化和节日习俗。

Icy planets and moons bypassing the habitable state

Profs.Yang Jun(杨军)and Hu Yongyun(胡永云)at the Department of Atmospheric and Oceanic Sciences,School of Physics,Peking University,and their collaborators recently published a paper in Nature Geoscience(http://www.nature.com/ngeo/journal/v10/n8/pdf/ngeo2994.pdf).They show

Commercial Moon Landings Multiply

Along with its familiar impact craters,the surface of the Moon sports numerous pale whorls and streaks known as lunar swirls[1].Likened to the pattern produced when someone pours cream into a cup of black coffee[2],the swirls can extend for more than 50 km and have puzzled researchers for centuries[3].Adding to their mystery,the features are associated with regions of magnetized rocks,an unusual attribute because the Moon lacks a magnetic field[3].Researchers do not know how the swirls are related to the magnetic fields or how they formed.

The Cause and Prevention of Major Earthquakes in the World

On February 6, 2023, a series of severe earthquakes occurred in eastern Turkey and neighboring areas of Syria. It was the largest earthquake in the world in more than a year, and the largest earthquake in the history of Turkey. Living under the fear of earthquakes, the people in Turkey and other earthquake zones have hoped again and again to change their fate, but they have to resign themselves to fate. Thus, the author analyzed the causes of large earthquakes such as Turkey earthquake, and found that some of the world’s potential seismic zones have been eroded by sea water or river water for a long time to create a series of surface faults. When the moon gets close to these faults, it will have a huge gravitational pull on them, and even cause the fault to move, resulting in strong earthquakes. Especially in some seismic zones, earthquakes are occurring more and more frequently and their intensity is getting bigger and bigger. The main reason is that the opening of the Arctic shipping route and the exploration and exploitation of oil and gas have caused the melting of the Arctic ice sheet and the loss of glaciers, which has led to the weakening of the Arctic vortex and the reduction of the compression ability of the polar vortices to the clouds, thus slowing down the rotation of the Earth and thus the revolution of the moon. So the moon gradually moves in a spiral toward the Earth;as the moon orbit close to the Earth, the moon’s gravity on the surface faults will gradually strengthen, so it is easy to cause the surface fault dislocations, resulting in frequent earthquakes or strong earthquakes. So the author puts forward some measures to prevent frequent and strong earthquakes.

2023 Mid-Autumn Festival:A Moonmoment to Remember Global Celebration Activities

From September 22 to October 6,the global unified brand activities,"2023 Mid-Autumn Festival:A Moonmoment to Remember"was held,creating a festive atmosphere across the world through performances,exhibitions,temple fairs,competitions,interactive experiences,cultural salons and other activities,enhance the engagement and experience of local citizens,and letting people from all over the world share the happy and peaceful atmosphere of the Mid-Autumn Festival with Chinese people.

一种采用容器技术基于通用硬件的云计算轨道交通信号控制系统安全平台

轨道交通信号领域的既有SIL4级安全产品架构通常采用嵌入式板卡,以满足高实时性、高安全性和低功耗的要求。但受到半导体专用硬件的短生命周期影响,且嵌入式板卡受限于CPU的性能无法满足日益扩大的运算能力的要求。随着线路的不断开通和拓展,新站点的信号控制系统建设、运行、维护成本不断增加产生了分散布局的成本累计问题。本文针对上述存在的问题,研究设计了一种采用容器技术基于通用硬件(COTS)的云计算架构安全平台,安全完整度达到SIL4,给轨道交通信号控制系统提供了一种解决过时硬件、并整合了资源减少了业务系统的建设、运行、维护成本,而且还提供了高可伸缩性(可重用性、可分配性、可伸缩性)的解决方案。

合作视角下的深空科学:月球与金星

The paper gives a brief review of the upcoming Russian moon and Venus robotic exploration missions,including objectives and cooperation opportunities.It also introduces the joint Russia-China International Lunar Research Station(ILRS)program from perspective of cooperation in space science.

真实自然的瑞典之声 Moonriver Audio(月亮河)Model 404合并式功放

说起音响品牌的名字,相信大家见得最多的应该是创始人的姓名,其次就是关于器材特色的描述,还有一些是品牌所在城市的地方等等。但,以一首经典歌曲的名字作为品牌名的,你见过没有?来自瑞典的Moonriver Audio,就是受到了著名歌曲《Moon River》的启发。

课外空间

Emily of New Moon《新月的艾米莉》Emily Starr never knew what it was to be lonelyl-until her dear father died.The she was taken to live with her aunt Elizabeth at New Moon Farm.Emily's sure she'll never be happy there,because of her terrible aunt and the classmates.艾米莉·斯塔尔从来不知道孤独是什么感觉,直到她亲爱的父亲去世。她被带到新月农场与伊丽莎白阿姨住在一起。因为有让人讨厌的阿姨和同学,艾米莉确信她在那里永远不会快乐。

国际月球天文台、银河论坛与深空探测国际合作

The International Lunar Observatory Association(ILOA) is an inter-global enterprise incorporated in Hawai’i as a non-profit organization in 2007 to advance human understanding the cosmos through observation of the moon, helping to realize long-term astronomical and scientific exploration of the moon’s South Pole, and participate in a human lunar base build-out-with Aloha. ILOA has an international board of 28 Directors from around the world. Science education and public engagement have been fundamental principles for ILOA since its inception in 2007.

A Space-Flight Ship Travelling by a Plasma Rocket Engine from the Earth Ground to the Moon

Since a thrust of an ion rocket engine is much weaker than the one of a chemical fuel engine, nowadays, ion engines are used mainly in spaces where gravities are very weak. Here, as a powerful plasma rocket to make a heavy ship get out from the gravity-sphere of the earth without relying on an atomic power rocket, an ion-velocity booster is investigated. It is a main challenge how to protect the engine wall from the melting due to collisions of ions which grow into high-energy particles.

月球的地体构造与起源模式

按照月球表面物质成分分布的特点,月壳可以划分为三个主要的化学地体:1)风暴洋克里普地体(PKT);2)斜长质高地地体(FHT);3)南极爱特肯地体(SPAT),综合对比天体化学和固体地球科学研究的前缘和热点,本文建立了月球地体构造及其起源的星子堆积模式,对月球化学分布的不均匀性的起因给出了较为简单和合理的解释。

磁共振波谱技术及其在神经科学研究领域中的应用

1973年Moon和Richard等利用磁共振波谱分析（magnetic resonance spectroscopy,MRS）技术对离体红细胞的特征物质变化进行了测定。这一研究成为MRS技术在生物学领域应用的开端。