DOCSLIB.ORG

Space Physics Project the Moons of the Planets

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Space Physics Project the Moons of the Planets Space Physics Project The Moons of the Planets Ria Becker October 27, 2008 Contents 1 Contents 1 Introduction 2 2 Definitions 2 3 The Earth's Moon 3 4 The Moons of Mars 3 4.1 Phobos . 3 4.2 Deimos . 4 5 The Moons of Jupiter 4 5.1 Io........................................... 5 5.2 Europa . 5 5.3 Ganymede . 6 5.4 Callisto . 6 6 The Moons of Saturn 7 6.1 Titan . 7 6.2 Enceladus . 8 6.3 Mimas . 8 6.4 Hyperion . 9 6.5 Epimetheus and Janus . 9 7 The Moons of Uranus 9 8 The Moons of Neptun 10 8.1 Triton . 10 1 Introduction 2 1 Introduction The aim of this project is to give an overview over the different moons of the planets in our solar system. The longest and best known is naturally the Earth's moon. In 1610 discovered Galileo Galilei four moons of Jupiter: Io, Europa, Ganymede and Callisto. Those where the first celestial objects confirmed to orbit an body other than the Earth. Until today there are more than 165 confirmed moons in the solar system discovered and the number of moons belonging to a planet differs greatly. The Earth has one large one, Mars has two small ones, Jupiter and Saturn have about 60, Uranus has 27 and Neptun 13. In contrary to that Mer- cury and Venus possess no natural satellites. Due to this large number of moons in the solar system, this report covers only the most interesting ones. Figure 1: Selected moons of the solar system [1]. 2 Definitions A moon or natural satellite is a body, which orbits a planet or smaller body (e.g. dwarf planet), called primary. Satellites can be classified in regular and irregular ones. Former are those which orbit rela- tively circular and close to the planet. They are tidally locked, that means they are always facing the same side towards its primary. Mostly it is believed that regular satellites are often formed at the same time and place like the planet. Irregular satellites often orbit inclined and are too far away from the planet to be tidally locked. It is presumed that they have been captured by their primary. 3 The Earth's Moon 3 3 The Earth's Moon The Earth's Moon is the fifth largest satel- lite in the solar system. It has a diame- ter of 3; 500 km, which is approximately one fourth of the Earth's diameter. The distance between Moon and Earth is approximately sixty times the radius of the Earth, which is 384; 400 km. Due to tidal effects of the Moon on the Earth and conservation of an- gular momentum is this distance increasing each year by 3:8 cm. This slows also the ro- tation of the Earth down by 0:002 seconds per day per century.With a mass density of 3; 341 g/cm3 the Moon is about 81 times lighter than the Earth. The Moon orbits the Earth in 27.3 days and since it is a regu- Figure 2: The moon as seen by an observer on lar satellite, it faces always the same side to the Earth [1]. the Earth. The atmosphere is negligible and the temperature of the surface differs between lunar day (about 107◦C) and night (about −153◦C). It is believed that the formation of the Moon was about 4:5 billion years ago. There are different speculations about the process whereas today the giant impact hypothesis is pre- vailed. Therefore a Mars-sized body collided with the proto-Earth, whereby a huge amount of material was thrown into the orbit and accreted to the Moon. The surface of the Moon is one of the poorest reflector in the solar system, it reflects only about 7% of incident light. A dry ashen layer (called Regolith) covers the surface, on which all-around impact craters can be found. This shows the absence of strong erosion and any geological activity. The Moon is the only celestial body which humans have traveled to or even landet upon. There where about six Moon landings between 1969 and 1972. 4 The Moons of Mars Mars has two tiny satellites, Phobos and Deimos, which are presumably captured asteroids and were discovered in 1877. Until now there is no satisfactory theory about the reason why those two bodies came into the orbit of Mars. Both, Phobos and Deimos, are tidally locked to its primary. They have a lower albedo than the Earth's Moon and their surface is therefore very low-reflective. 4.1 Phobos Phobos (Fig. 3a) is irregularly shaped, its size is 27 × 21:6 × 18:8 km. The distance to the Mars is only 9377 km and therefore has Phobos the smallest orbit of all known planetary moons. The orbital period is only 7:66 hours. Since the rotational period of Mars is 24:6 hours, Phobos rises twice each day in the west and sets in the east. The fast orbital velocity leads also to a declining of the orbit from which follows that in a few ten millions of years Phobos will crash into Mars. The density of Phobos is about 1:9 g/cm3. It is too low to 5 The Moons of Jupiter 4 (a) Phobos, obtained by Mars Reconnaissance Or- (b) Deimos, image taken by the Viking 1 orbiter. biter. Figure 3: Moons of Mars [1]. be solid rock and therefore there is a suggestion that Phobos might contain a substantial reservoir of ice. Yet this presumption has not been ruled out by spectral observations. 4.2 Deimos Deimos (Fig. 3b) is smaller than Phobos, with a size of only 10 × 12 × 16 km. As it can be seen in Figure 3b, it is also highly non-spherical. The orbital period of Deimos is 30:35 hours which means it orbits slower than Mars rotates. This leads to an increasing orbit and the fact, that Deimos rises in the east and sets in west in contrary to Phobos. 5 The Moons of Jupiter Jupiter, which is the largest planet of the solar system with a radius of 71398 km has until now 62 confirmed moons. This is the highest number of satellites belonging to one planet. Not all of them have yet been named. There are eight regular moons and the rest of them is tiny and irregular, that means their orbits have high inclinations and eccentricities. Those are mostly captured from solar orbits. The most famous are the four regular Galilean satellites: Io, Europa, Ganymede and Callisto, listed in the order of increasing distance from Jupiter. Europa, the smallest of them, is about 5000 times more massive than all of the non-Galilean moons of Jupiter combined. The physical and orbital characteristics of the satellites differ greatly, from nearly circular to highly eccentrical orbits as well as diameters of barely 1 km to 5262 km, which is the diameter of Ganymede, the largest satellite of the solar system. The orbital periods vary likewise: from a period of seven hours to almost three earth years. Due to the large number of moons in the following only the four Galilean satellites are presented. 5 The Moons of Jupiter 5 5.1 Io Io (Fig. 4a) is the innermost of the Galilean satellites and the fifth moon out from Jupiter. It has a diameter of 3642 km and is therefore the fourth largest moon in the solar system and slightly greater than the Moon of the Earth. The orbit of Io has a distance of 421700 km from the center of Jupiter and a period of 42:5 hours. It is tidally locked to its primary and thus is Io a regular satellite. Io is the most geological active object in the solar system. It has more than 400 active volcanos on its surface. There can be found almost no impact craters due to large surface changes caused by volcanic plumes an lava flows. Those colored the surface in different shades of red, yellow, white, black and green. This geological activity results from the tidal heating. Since Io is in orbital resonance with Europa and Ganymede which maintains Io in its orbit, the tidal dissipation leads to a significant heating in the interior. On Io more than 100 mountains can be found whereas some are taller than the Mount Everest on the Earth are. Large parts of the surface are coated with sulfur and sulfur dioxide frost. The interior of Io consists mainly of silicate rock an iron. This causes a density of 3:53 g/cm3, which is higher than that of any other satellite in the solar system. It is also significantly higher than the density of the other Galilean moons. In contrary to them Io has almost no water. There is an extremely thin atmosphere, which consists mainly of sulfur dioxide. 5.2 Europa Europa (Fig. 4b) is the sixth moon out from Jupiter. With a diameter of 3122 km slightly smaller than Earth's Moon and the sixth largest in the solar system. It is a regular satellite and has an orbital period of 3.55 days. The orbit is slightly eccentric due to gravitational disturbances from the other Galilean moons. Since Europa is in orbital resonance with Io and Ganymede the tidal flexing produces also an internal heating. Europa has a tenuous atmosphere consisting of oxygen. The interior of Europa is mainly silicate rock and there is an iron core. The outer layer of about 100 km consists of water (a) Io. (b) Europa. Figure 4: Two inner Galilean Satellites, images taken by NASA's Galileo spacecraft [1].
Load more

Recommended publications
  • JUICE Red Book
    ESA/SRE(2014)1 September 2014 JUICE JUpiter ICy moons Explorer Exploring the emergence of habitable worlds around gas giants Definition Study Report European Space Agency 1 This page left intentionally blank 2 Mission Description Jupiter Icy Moons Explorer Key science goals The emergence of habitable worlds around gas giants Characterise Ganymede, Europa and Callisto as planetary objects and potential habitats Explore the Jupiter system as an archetype for gas giants Payload Ten instruments Laser Altimeter Radio Science Experiment Ice Penetrating Radar Visible-Infrared Hyperspectral Imaging Spectrometer Ultraviolet Imaging Spectrograph Imaging System Magnetometer Particle Package Submillimetre Wave Instrument Radio and Plasma Wave Instrument Overall mission profile 06/2022 - Launch by Ariane-5 ECA + EVEE Cruise 01/2030 - Jupiter orbit insertion Jupiter tour Transfer to Callisto (11 months) Europa phase: 2 Europa and 3 Callisto flybys (1 month) Jupiter High Latitude Phase: 9 Callisto flybys (9 months) Transfer to Ganymede (11 months) 09/2032 – Ganymede orbit insertion Ganymede tour Elliptical and high altitude circular phases (5 months) Low altitude (500 km) circular orbit (4 months) 06/2033 – End of nominal mission Spacecraft 3-axis stabilised Power: solar panels: ~900 W HGA: ~3 m, body fixed X and Ka bands Downlink ≥ 1.4 Gbit/day High Δv capability (2700 m/s) Radiation tolerance: 50 krad at equipment level Dry mass: ~1800 kg Ground TM stations ESTRAC network Key mission drivers Radiation tolerance and technology Power budget and solar arrays challenges Mass budget Responsibilities ESA: manufacturing, launch, operations of the spacecraft and data archiving PI Teams: science payload provision, operations, and data analysis 3 Foreword The JUICE (JUpiter ICy moon Explorer) mission, selected by ESA in May 2012 to be the first large mission within the Cosmic Vision Program 2015–2025, will provide the most comprehensive exploration to date of the Jovian system in all its complexity, with particular emphasis on Ganymede as a planetary body and potential habitat.
    [Show full text]
  • The Subsurface Habitability of Small, Icy Exomoons J
    A&A 636, A50 (2020) Astronomy https://doi.org/10.1051/0004-6361/201937035 & © ESO 2020 Astrophysics The subsurface habitability of small, icy exomoons J. N. K. Y. Tjoa1,?, M. Mueller1,2,3, and F. F. S. van der Tak1,2 1 Kapteyn Astronomical Institute, University of Groningen, Landleven 12, 9747 AD Groningen, The Netherlands e-mail: [email protected] 2 SRON Netherlands Institute for Space Research, Landleven 12, 9747 AD Groningen, The Netherlands 3 Leiden Observatory, Leiden University, Niels Bohrweg 2, 2300 RA Leiden, The Netherlands Received 1 November 2019 / Accepted 8 March 2020 ABSTRACT Context. Assuming our Solar System as typical, exomoons may outnumber exoplanets. If their habitability fraction is similar, they would thus constitute the largest portion of habitable real estate in the Universe. Icy moons in our Solar System, such as Europa and Enceladus, have already been shown to possess liquid water, a prerequisite for life on Earth. Aims. We intend to investigate under what thermal and orbital circumstances small, icy moons may sustain subsurface oceans and thus be “subsurface habitable”. We pay specific attention to tidal heating, which may keep a moon liquid far beyond the conservative habitable zone. Methods. We made use of a phenomenological approach to tidal heating. We computed the orbit averaged flux from both stellar and planetary (both thermal and reflected stellar) illumination. We then calculated subsurface temperatures depending on illumination and thermal conduction to the surface through the ice shell and an insulating layer of regolith. We adopted a conduction only model, ignoring volcanism and ice shell convection as an outlet for internal heat.
    [Show full text]
  • Long-Term Orbital and Rotational Motions of Ceres and Vesta T
    A&A 622, A95 (2019) Astronomy https://doi.org/10.1051/0004-6361/201833342 & © ESO 2019 Astrophysics Long-term orbital and rotational motions of Ceres and Vesta T. Vaillant, J. Laskar, N. Rambaux, and M. Gastineau ASD/IMCCE, Observatoire de Paris, PSL Université, Sorbonne Université, 77 avenue Denfert-Rochereau, 75014 Paris, France e-mail: [email protected] Received 2 May 2018 / Accepted 24 July 2018 ABSTRACT Context. The dwarf planet Ceres and the asteroid Vesta have been studied by the Dawn space mission. They are the two heaviest bodies of the main asteroid belt and have different characteristics. Notably, Vesta appears to be dry and inactive with two large basins at its south pole. Ceres is an ice-rich body with signs of cryovolcanic activity. Aims. The aim of this paper is to determine the obliquity variations of Ceres and Vesta and to study their rotational stability. Methods. The orbital and rotational motions have been integrated by symplectic integration. The rotational stability has been studied by integrating secular equations and by computing the diffusion of the precession frequency. Results. The obliquity variations of Ceres over [ 20 : 0] Myr are between 2◦ and 20◦ and the obliquity variations of Vesta are between − 21◦ and 45◦. The two giant impacts suffered by Vesta modified the precession constant and could have put Vesta closer to the resonance with the orbital frequency 2s s . Given the uncertainty on the polar moment of inertia, the present Vesta could be in this resonance 6 − V where the obliquity variations can vary between 17◦ and 48◦.
    [Show full text]
  • Abstracts of the 50Th DDA Meeting (Boulder, CO)
    Abstracts of the 50th DDA Meeting (Boulder, CO) American Astronomical Society June, 2019 100 — Dynamics on Asteroids break-up event around a Lagrange point. 100.01 — Simulations of a Synthetic Eurybates 100.02 — High-Fidelity Testing of Binary Asteroid Collisional Family Formation with Applications to 1999 KW4 Timothy Holt1; David Nesvorny2; Jonathan Horner1; Alex B. Davis1; Daniel Scheeres1 Rachel King1; Brad Carter1; Leigh Brookshaw1 1 Aerospace Engineering Sciences, University of Colorado Boulder 1 Centre for Astrophysics, University of Southern Queensland (Boulder, Colorado, United States) (Longmont, Colorado, United States) 2 Southwest Research Institute (Boulder, Connecticut, United The commonly accepted formation process for asym- States) metric binary asteroids is the spin up and eventual fission of rubble pile asteroids as proposed by Walsh, Of the six recognized collisional families in the Jo- Richardson and Michel (Walsh et al., Nature 2008) vian Trojan swarms, the Eurybates family is the and Scheeres (Scheeres, Icarus 2007). In this theory largest, with over 200 recognized members. Located a rubble pile asteroid is spun up by YORP until it around the Jovian L4 Lagrange point, librations of reaches a critical spin rate and experiences a mass the members make this family an interesting study shedding event forming a close, low-eccentricity in orbital dynamics. The Jovian Trojans are thought satellite. Further work by Jacobson and Scheeres to have been captured during an early period of in- used a planar, two-ellipsoid model to analyze the stability in the Solar system. The parent body of the evolutionary pathways of such a formation event family, 3548 Eurybates is one of the targets for the from the moment the bodies initially fission (Jacob- LUCY spacecraft, and our work will provide a dy- son and Scheeres, Icarus 2011).
    [Show full text]
  • 15:1 Resonance Effects on the Orbital Motion of Artificial Satellites
    doi: 10.5028/jatm.2011.03032011 Jorge Kennety S. Formiga* FATEC - College of Technology 15:1 Resonance effects on the São José dos Campos/SP – Brazil [email protected] orbital motion of artificial satellites Rodolpho Vilhena de Moraes Abstract: The motion of an artificial satellite is studied considering Federal University of São Paulo geopotential perturbations and resonances between the frequencies of the São José dos Campos/SP – Brazil mean orbital motion and the Earth rotational motion. The behavior of the [email protected] satellite motion is analyzed in the neighborhood of the resonances 15:1. A suitable sequence of canonical transformations reduces the system of differential equations describing the orbital motion to an integrable kernel. *author for correspondence The phase space of the resulting system is studied taking into account that one resonant angle is fixed. Simulations are presented showing the variations of the semi-major axis of artificial satellites due to the resonance effects. Keywords: Resonance, Artificial satellites, Celestial mechanics. INTRODUCTION some resonance’s region. In our study, it satellites in the neighbourhood of the 15:1 resonance (Fig. 1), or satellites The problem of resonance effects on orbital motion with an orbital period of about 1.6 hours will be considered. of satellites falls under a more categorical problem In our choice, the characteristic of the 356 satellites under in astrodynamics, which is known as the one of zero this condition can be seen in Table 1 (Formiga, 2005). divisors. The influence of resonances on the orbital and translational motion of artificial satellites has been extensively discussed in the literature under several aspects.
    [Show full text]
  • The Effect of Close-In Giant Planets' Evolution on Tidal-Induced Migration of Exomoons
    MNRAS 000, 1–9 (2017) Preprint 2 December 2019 Compiled using MNRAS LATEX style file v3.0 The effect of close-in giant planets’ evolution on tidal-induced migration of exomoons J. A. Alvarado-Montes⋆, Jorge I. Zuluaga and Mario Sucerquia Solar, Earth and Planetary Physics Group (SEAP) Computational Physics and Astrophysics Group (FACom) Instituto de F´ısica - FCEN, Universidad de Antioquia, Colombia Calle 70 No. 52-21, Medell´ın, Colombia Accepted 2017 July 8. Received 2017 July 8; in original form 2017 April 6 ABSTRACT Hypothetical exomoons around close-in giant planets may migrate inwards and/or outwards in virtue of the interplay of the star, planet and moon tidal interactions. These processes could be responsible for the disruption of lunar systems, the collision of moons with planets or could provide a mechanism for the formation of exorings. Several models have been developed to determine the fate of exomoons when subject to the tidal effects of their host planet. None of them have taken into account the key role that planetary evolution could play in this process. In this paper we put together numerical models of exomoon tidal-induced orbital evolution, results of planetary evo- lution and interior structure models, to study the final fate of exomoons around evolv- ing close-in gas giants. We have found that planetary evolution significantly affects not only the time-scale of exomoon migration but also its final fate. Thus, if any change in planetary radius, internal mass distribution and rotation occurs in time-scales lower or comparable to orbital evolution, exomoon may only migrate outwards and prevent tidal disruption or a collision with the planet.
    [Show full text]
  • Orbital Resonances and Chaos in the Solar System
    Solar system Formation and Evolution ASP Conference Series, Vol. 149, 1998 D. Lazzaro et al., eds. ORBITAL RESONANCES AND CHAOS IN THE SOLAR SYSTEM Renu Malhotra Lunar and Planetary Institute 3600 Bay Area Blvd, Houston, TX 77058, USA E-mail: [email protected] Abstract. Long term solar system dynamics is a tale of orbital resonance phe- nomena. Orbital resonances can be the source of both instability and long term stability. This lecture provides an overview, with simple models that elucidate our understanding of orbital resonance phenomena. 1. INTRODUCTION The phenomenon of resonance is a familiar one to everybody from childhood. A very young child is delighted in a playground swing when an older companion drives the swing at its natural frequency and rapidly increases the swing amplitude; the older child accomplishes the same on her own without outside assistance by driving the swing at a frequency twice that of its natural frequency. Resonance phenomena in the Solar system are essentially similar – the driving of a dynamical system by a periodic force at a frequency which is a rational multiple of the natural frequency. In fact, there are many mathematical similarities with the playground analogy, including the fact of nonlinearity of the oscillations, which plays a fundamental role in the long term evolution of orbits in the planetary system. But there is also an important difference: in the playground, the child adjusts her driving frequency to remain in tune – hence in resonance – with the natural frequency which changes with the amplitude of the swing. Such self-tuning is sometimes realized in the Solar system; but it is more often and more generally the case that resonances come-and-go.
    [Show full text]
  • Resonant Moons of Neptune
    EPSC Abstracts Vol. 13, EPSC-DPS2019-901-1, 2019 EPSC-DPS Joint Meeting 2019 c Author(s) 2019. CC Attribution 4.0 license. Resonant moons of Neptune Marina Brozović (1), Mark R. Showalter (2), Robert A. Jacobson (1), Robert S. French (2), Jack L. Lissauer (3), Imke de Pater (4) (1) Jet Propulsion Laboratory, California Institute of Technology, California, USA, (2) SETI Institute, California, USA, (3) NASA Ames Research Center, California, USA, (4) University of California Berkeley, California, USA Abstract We used integrated orbits to fit astrometric data of the 2. Methods regular moons of Neptune. We found a 73:69 inclination resonance between Naiad and Thalassa, the 2.1 Observations two innermost moons. Their resonant argument librates around 180° with an average amplitude of The astrometric data cover the period from 1981-2016, ~66° and a period of ~1.9 years. This is the first fourth- with the most significant amount of data originating order resonance discovered between the moons of the from the Voyager 2 spacecraft and HST. Voyager 2 outer planets. The resonance enabled an estimate of imaged all regular satellites except Hippocamp the GMs for Naiad and Thalassa, GMN= between 1989 June 7 and 1989 August 24. The follow- 3 -2 3 0.0080±0.0043 km s and GMT=0.0236±0.0064 km up observations originated from several Earth-based s-2. More high-precision astrometry of Naiad and telescopes, but the majority were still obtained by HST. Thalassa will help better constrain their masses. The [4] published the latest set of the HST astrometry GMs of Despina, Galatea, and Larissa are more including the discovery and follow up observations of difficult to measure because they are not in any direct Hippocamp.
    [Show full text]
  • Arxiv:1603.07071V1
    Dynamical Evidence for a Late Formation of Saturn’s Moons Matija Cuk´ Carl Sagan Center, SETI Institute, 189 North Bernardo Avenue, Mountain View, CA 94043 [email protected] Luke Dones Southwest Research Institute, Boulder, CO 80302 and David Nesvorn´y Southwest Research Institute, Boulder, CO 80302 Received ; accepted Revised and submitted to The Astrophysical Journal arXiv:1603.07071v1 [astro-ph.EP] 23 Mar 2016 –2– ABSTRACT We explore the past evolution of Saturn’s moons using direct numerical in- tegrations. We find that the past Tethys-Dione 3:2 orbital resonance predicted in standard models likely did not occur, implying that the system is less evolved than previously thought. On the other hand, the orbital inclinations of Tethys, Dione and Rhea suggest that the system did cross the Dione-Rhea 5:3 resonance, which is closely followed by a Tethys-Dione secular resonance. A clear implica- tion is that either the moons are significantly younger than the planet, or that their tidal evolution must be extremely slow (Q > 80, 000). As an extremely slow-evolving system is incompatible with intense tidal heating of Enceladus, we conclude that the moons interior to Titan are not primordial, and we present a plausible scenario for the system’s recent formation. We propose that the mid-sized moons re-accreted from a disk about 100 Myr ago, during which time Titan acquired its significant orbital eccentricity. We speculate that this disk has formed through orbital instability and massive collisions involving the previous generation of Saturn’s mid-sized moons. We identify the solar evection resonance perturbing a pair of mid-sized moons as the most likely trigger of such an insta- bility.
    [Show full text]
  • The Excited Spin State of Dimorphos Resulting from the DART Impact
    Highlights The Excited Spin State of Dimorphos Resulting from the DART Impact Harrison F. Agrusa,Ioannis Gkolias,Kleomenis Tsiganis,Derek C. Richardson,Alex J. Meyer,Daniel J. Scheeres,Matija Ćuk,Seth A. Jacobson,Patrick Michel,Özgür Karatekin,Andrew F. Cheng,Masatoshi Hirabayashi,Yun Zhang,Eugene G. Fahnestock,Alex B. Davis • High-fidelity numerical codes are essential for modeling the long-term spin evolution • DART may excite Dimorphos’ spin, leading to attitude instability and chaotic tumbling • Dimorphos is especially prone to unstable rotation about its long axis • A chaotic spin state will affect the system’s BYORP and tidal evolution • ESA’s Hera mission may be able to place constraints on the system’s tidal parameters arXiv:2107.07996v2 [astro-ph.EP] 29 Jul 2021 The Excited Spin State of Dimorphos Resulting from the DART Impact a < b b a Harrison F. Agrusa , , Ioannis Gkolias , Kleomenis Tsiganis , Derek C. Richardson , Alex c c d e f J. Meyer , Daniel J. Scheeres , Matija Ćuk , Seth A. Jacobson , Patrick Michel , g h i f Özgür Karatekin , Andrew F. Cheng , Masatoshi Hirabayashi , Yun Zhang , Eugene j j G. Fahnestock and Alex B. Davis aDepartment of Astronomy, University of Maryland, College Park, MD, USA bDepartment of Physics, Aristotle University of Thessaloniki, GR 54124 Thessaloniki, Greece cSmead Department of Aerospace Engineering Sciences, University of Colorado Boulder, Boulder, CO, USA dCarl Sagan Center, SETI Institute, Mountain View, CA, USA eDepartment of Earth and Environmental Sciences, Michigan State University,
    [Show full text]
  • Orbital Resonance and Solar Cycles by P.A.Semi
    Orbital resonance and Solar cycles by P.A.Semi Abstract We show resonance cycles between most planets in Solar System, of differing quality. The most precise resonance - between Earth and Venus, which not only stabilizes orbits of both planets, locks planet Venus rotation in tidal locking, but also affects the Sun: This resonance group (E+V) also influences Sunspot cycles - the position of syzygy between Earth and Venus, when the barycenter of the resonance group most closely approaches the Sun and stops for some time, relative to Jupiter planet, well matches the Sunspot cycle of 11 years, not only for the last 400 years of measured Sunspot cycles, but also in 1000 years of historical record of "severe winters". We show, how cycles in angular momentum of Earth and Venus planets match with the Sunspot cycle and how the main cycle in angular momentum of the whole Solar system (854-year cycle of Jupiter/Saturn) matches with climatologic data, assumed to show connection with Solar output power and insolation. We show the possible connections between E+V events and Solar global p-Mode frequency changes. We futher show angular momentum tables and charts for individual planets, as encoded in DE405 and DE406 ephemerides. We show, that inner planets orbit on heliocentric trajectories whereas outer planets orbit on barycentric trajectories. We further TRY to show, how planet positions influence individual Sunspot groups, in SOHO and GONG data... [This work is pending...] Orbital resonance Earth and Venus The most precise orbital resonance is between Earth and Venus planets. These planets meet 5 times during 8 Earth years and during 13 Venus years.
    [Show full text]
  • Martian Moon's Orbit Hints at an Ancient Ring of Mars
    Martian Moon’s Orbit Hints at an Ancient Ring of Mars PRESS RELEASE DATE June 2, 2020 CONTACT Rebecca McDonald Director of Communications SETI Institute [email protected] +1 650-960-4526 Photo credit: https://solarsystem.nasa.gov/moons/mars-moons/deimos/in-depth/ June 2, 2020, Mountain View, CA – Scientists from the SETI Institute and Purdue University have found that the only way to produce Deimos’s unusually tilted orbit is for Mars to have had a ring billions of years ago. While some of the more massive planets in our solar system have giant rings and numerous big moons, Mars only has two small, misshapen moons, Phobos and Deimos. Although these moons are small, their peculiar orbits hide important secrets about their past. For a long time, scientists believed that Mars’s two moons, discovered in 1877, were captured asteroids. However, since their orbits are almost in the same plane as Mars’s equator, that the moons must have formed at the same time as Mars. But the orbit of the smaller, more distant moon Deimos is tilted by two degrees. “The fact that Deimos’s orbit is not exactly in plane with Mars’s equator was considered unimportant, and nobody cared to try to explain it,” says lead author Matija Ćuk, a research scientist at the SETI Institute. “But once we had a big new idea and we looked at it with new eyes, Deimos’s orbital tilt revealed its big secret.” This significant new idea was put forward in 2017 byĆ uk’s co-author David Minton, professor at Purdue University and his then-graduate student Andrew Hesselbrock.
    [Show full text]