A developed model has been put for the hypothesis of capturing moons in explaining the origin of Jupiter moons, and study the change of the orbital properties of these satellites as well as the distance from the planet. Jupiter moons were divided into two types according to their physical and orbital properties, they are the moons , which are formed from the same material as the planet, so it was named the original moons ,while the moons that have been captured from the surrounding space was renamed exotic moons . And the moons of exotic origin asteroid belt and the Kuiper belt in the region which is behind Neptune, the origin of each clique of moons is an asteroid fragmented after colliding previously with another body and then gathered again by simple gravity of its parts among them, and then it has been disintegrated once again due to the influence of the gravity of the planet against it, and the process of captivity are due to the gravitational interaction between the asteroid or comet and the planet when one of them enters within Hill ball to Jupiter.
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to better understand their magnetic fields and their plasma [charged particle] environment. Studying other planets always helps us better understand the Earth, and this is true when we study Jupiter's radio emission. Earth also emits radio waves by similar processes, so we can better understand this process by listening to Jupiter from both ground-based and space-based radio antennas. Not only can we learn about why the radio waves are created and how they move through space, we can also learn about the interior of Jupiter and about Jupiter's moons. Radio waves are generated because the planet has a magnetic field. This magnetic field originates deep in the interior of the planet, and the overall strength of the magnetic field directly affects the type of radio emission emitted by the planet. This helps us with the theory of how the magnetic field is created in the interior, and in determining the composition of the various interior layers.
main sequence, then passing through the giant branch (and hence losing mass), before settling into the white dwarf phase. The stellar mass-loss causes the planetary semimajor axes to expand, and can trigger late instability. We use here an ensemble of 119 of these sim- ulations, which all featured planets that remained stable and packed throughout the main sequence and giant branch phase, before suffer- ing their first mutual close encounter along the white dwarf phase. These 119 simulations include four- and ten-planet systems, as well as planets with the mass of Jupiter, Saturn, Neptune, Uranus, Earth, and planets with masses down to 0.046 Earth masses. Payne et al. (2016) investigated a subset of these simulations and determined that the distribution of close approaches between the planets of these simulations could efficiently eject moons from a wide range of circumplanetary orbits. In this investigation, we wish to under- stand where these moons ultimately go to, once they are liberated from circumplanetary orbit.
It is believed that the regular satellites of Jupiter, Saturn and Uranus formed within a circumplanetary disk, as this explains the circular orbits of the regular satellites and their low inclination with respect to planetary rotation. In the literature, there are two main models describing the method by which a disk of gas and solids is processed into a small number of large satellites, that of Canup & Ward (2006) and Mosqueira & Estrada (2003a,b). Canup & Ward (2006) use a time-dependant, single component circumplanetary disk model to investigate regular satellite formation. They suggest that the properties, in particular, the mass of regular satellites within this disk is determined by the balance between the rate of accretion of material onto the proto-moons, and orbital decay of these protomoons within the accretion disk onto the growing gas giant. This process results in a set of approximately 4 large moons within 60 planetary radii of the planet, with total mass approximately one ten thousandth of their host planet. In comparison, Mosqueira & Estrada (2003a,b) propose a two-component disk model with a dense inner sub-disk extending out to the centrifugal radius, surrounded by a less dense outer disk. Unlike the model of Canup & Ward (2006), this model predicts that the migration timescale of moons is much longer than their formation timescale. While the model does not provide a firm limit on moon mass, it does predict that at most one large satellite should form outside the centrifugal radius.
The energetics pertinent to the zonostrophic regime suggests an explanation for another energy transfer conundrum as formulated by Ingersoll et al. (2004) for Jupiter and Suomi et al. (1991) for Neptune. The absorbed sunlight (power per unit area) on Jupiter and Neptune is, respectively, only 3.3% and 1/900th of that on Earth, but Jupiter’s and Neptune’s winds are, respectively, 3–4 and 6–7 times stronger, facts which seem to contradict each other. This contradiction is further accentuated by the arguments ad- vanced in Vallis (2006, p. 144): ‘‘Arguably, the magnitude of the velocity in the atmosphere and ocean is ultimately given by the strength of the forcing, and so ultimately by the differential heating between pole and equator.’’ It remains unmitigated by the subse- quent qualifying remark by Vallis, ‘‘although even this argument is not satisfactory, since the forcing mainly determines the energy throughput, not directly the energy itself, and the forcing is itself dependent on the atmosphere’s response.’’ Similar ideas can be traced in the scaling analysis of the deep convection theory by Showman et al. (2011) where the rate of the convective forcing is explicitly related to the strength of zonal jets.
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Figure 1: Approximate spectral energy distribution for the Sun, Jupiter, Venus, Mars, the Earth and a representative hot Jupiter. Both thermal and reflected components are plotted for each planet. Bandpasses of Kepler and Spitzer are indicated, showing which wavelength region of the planetary spectra are probed. Adapted from Seager 2003.
In preparation for welcoming our future workforce from China and improving our present Chinese language skills, our Employee- Management Liaison group - Team Jupiter (“they’re out of this world!”) - has provided yet another wonderful opportunity for personal
While there is a well-established trend between the irradiation of a hot Jupiter and the in ﬂ ation of its radius ( e.g., Enoch et al. 2012 ) , hot Jupiters also display a wide range of radii ( e.g., Burrows et al. 2007 ) . Sestovic et al. ( 2018 ) investigates the relationship between planet radius, mass, and irradiation, ﬁ nding that a more massive planet is usually less in ﬂ ated than a low-mass planet of the same temperature, due to the planet ’ s gravity counteracting the in ﬂ ation. In Figure 5 we show planetary radius as a function of equilibrium temperature, and use planetary mass as a third dimension, for all planets with 0.6 M Jup < M p < 4.0 M Jup as listed in the TEPCat database
The new findings support that wind speeds in the LRS have increased considerably over the wind speeds in the precursor storms. This had been observed by NASA's Voyager and Galileo missions in past decades. The latest wind speeds and directions were further measured using two image mosaics from New Horizons' telescopic Long Range Reconnaissance Imager (LORRI). New Horizons collected images from a distance of about 2.4 million kilometers from Jupiter at a resolution of 14.4 kilometers per pixel and obtained the maximum winds speeds between 155 and 190 meters per second far exceed the Category 5 storm on Earth. Jupiter's Great Red Spot has decreased steadily in size over the past few decades. Moreover, a rare "global upheaval" in Jupiter's atmosphere started which is involved in the disappearance of activity in the South Equatorial Belt and other spectacular cloud changes. New Horizons project scientists have reported that both the LRS and the GRS extend into the stratosphere to far higher altitudes than for the smaller storms on Jupiter.
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We have measured the alignment between the orbit of HATS-3b (a recently discovered, slightly inflated Hot Jupiter) and the spin axis of its host star. Data were obtained using the CYCLOPS2 optical-fiber bundle and its simultaneous calibration system feeding the UCLES spectrograph on the Anglo-Australian Telescope. The sky-projected spin–orbit angle of λ = 3 ◦ ± 25 ◦ was determined from spectroscopic measurements of the Rossiter–McLaughlin effect. This is the first exoplanet discovered through the HATSouth transit survey to have its spin–orbit angle measured. Our results indicate that the orbital plane of HATS-3b is consistent with being aligned to the spin axis of its host star. The low obliquity of the HATS-3 system, which has a relatively hot mid F-type host star, agrees with the general trend observed for Hot Jupiter host stars with effective temperatures >6250 K to have randomly distributed spin–orbit angles.
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A proxy for the impact rate was clearly needed, and we initially chose to use the number of comets that survived as the orbital integration proceeded. Over the course of the in- tegrations, comets were followed as they moved around the Sun until they hit Jupiter, Saturn or the Sun, or were ejected from the Solar System entirely. Since comets thrown to suf- ﬁciently large distances will clearly never return (even if their eccentricity is slightly less than one) due to the un-modelled gravitational eﬀects of nearby stars, the galactic tide and molecular clouds, the particles in our simulations were con- sidered ‘ ejected ’ when they reached a barycentric distance of 200 000 AU – twice the maximum initial aphelion distance. Note that our work focuses on comets after they have been sent inwards, so the fate of departing survivors beyond 200 000 AU is not of importance in our work.
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The results were used to create maps of the variability of the Earth’s orbital elements as a function of Jupiter’s initial semi-major axis and eccentricity. These maps, which build on earlier work studying the stability of proposed exoplanetary systems (e.g. ), give a quick visual guide to the degree to which the Earth’s Milankovitch cycles are influenced by small changes in the orbit of Jupiter, and we present a number of examples of such plots in the next section. We are currently in the process of taking the numerical results of our simulations (the orbital elements for the Earth across the various runs) and using them as input for simple climate models (e.g. ), to examine how the observed variability in Earth’s orbit might affect its climate. We anticipate that this analysis will be complete in the coming year.
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Taken in concert, our work will help us to uncover the degree to which fine tuning in planetary architecture can impact the climate, and potential habitability, of planets like the Earth. In doing so, it will give us a feel for how ‘unusual’ the Earth’s climatic variability is. A core tenant of the ‘Rare Earth’ philosophy (e.g. ) is that the Earth is unusually fortunate in its properties – almost a fluke of nature that just happens to be a safe haven in an inimical cosmos. It suggests that, for example, the impact rate at Earth is far lower than it would be were the giant planet Jupiter not present – in other words, that without our good fortune in having a giant protector, we would not be here. Whilst that particular aspect of the hypothesis has since been effectively demolished (see e.g. ), the idea underpinning the thesis remains under debate. Is the Earth unusually quiescent? Would most other ‘Earths’ be far less habitable than our own? Once we bring together climate modelling with our n-body simulations, we will begin to get a feel for just how precarious is Earth’s climate, in the context of the architecture of our own planetary system.
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A total of 31 bright (V < 6) solar-type stars was monitored throughout the whole 15-year survey. The main goal of the long-term studies of this sample was the search for Jupiter analogues. Despite the fact that the stars in the sample were selected for low activity levels, the more active stars turned out to be the most interesting targets. This contribution summarizes the most important results. The survey and its results for the whole sample are described in much more detail in Zechmeister et al. (2013).
In section 2, we explore another scenario, in which the interaction remains Alfvénic all along the tail and we show that the two model families predict similar tail lengths. Such an Alfvénic scenario explains very naturally why observations of the brightness vertical proﬁle in the tail shows no diﬀerence with the MAW spot proﬁle [Bonfond, 2010]. On the other hand, two diﬀerent mechanisms have been proposed to explain this similarity even if the tail was produced by a steady process [Matsuda et al., 2012]. However, we show simulation results indicating that neither of them could actually reproduce the observations (section 3). If the nature of the IFP tail is Alfvénic, with only a small amount of momentum loading arising from mass loading relative to the total momentum exchange of the interaction, then all three footprints on Jupiter could also have a tail, which we demonstrate in section 4.
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sion as stated by RASC-AL are: “Given a 20 year timespan starting in 2015, and a flat total NASA budget of $16 Billion a year, derive an architecture that delivers a crew of four to the surface of either Phobos or Deimos (or both) for a minimum of 300 days total. Lay out a series of Mars moons surface excursions driven by science, technology demonstration, ISRU and possible future human
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0.795. We can see from these examples that if all stars in the sample were stable and well observed (i.e., if selection effects, observing windows, and velocity jitter were unimportant), then every star would contribute 1.0 to the sum in Equation (2), giving a survey completeness of 1.0 (100%). We could then obtain the planet frequency simply by dividing the number of detections by the total number of stars. However, these effects are extremely important for long-term radial-velocity surveys, and so we use Equation (2) to obtain a more realistic estimate of the completeness of our entire sample as a function of orbital period. Those results are shown in Figure 13. We emphasize that we have not included unpublished planet candidates in our estimate of the frequency of Jupiter analogs. In Figure 13, we have summed over 101 stars, excluding 22 stars which exhibited an unusual artifact arising from the “correct-period” criterion discussed in Section 3.2. Consider a data set in which an injected signal with P in ∼ 3500 days results in P out = 5000 days being recovered by the periodogram. For a recovered signal to be accepted, it must be within 27.7% of the injected periodicity. So, for P in = 3612 days, P out = 5000 days is rejected, but at
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In the concluding part of n1y paper on tl1e occultation of Jupiter in April Jast (read 8th June), I referred to the question of Jupiter's intrinsic brilliancy, and expressed the hope that the question would be scientifically investigated .. In order to clear the way, I will first state the case. Jupiter is,.
The transit method has dominated the exoplanet detection game over the last decade. This technique has demonstrated a sensitivity to planets ranging from sub-Earths to super-Jupiters ( Fortney et al. 2011 ) orbiting a diverse array of stars, such as M-dwarfs ( Dressing & Charbonneau 2015 ) , giants ( Quinn et al. 2015 ) , and even binaries ( Doyle et al. 2011 ) . From 2010 – 2015, the number of con ﬁ rmed / validated exoplanets discovered via the transit method is seven-fold that of all other exoplanet hunting methods combined. Some of the last regions of parameter-space that have been stubbornly resistant to the reign of transits are those planets found beyond the snow-line, owing to their long orbital periods. Indeed, while ∼ 20 Jupiter analogs have been found with radial velocities ( Rowan et al. 2015 ) , no transiting examples have been previously announced.
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Before and after the Jupiter Orbit Insertion of Juno, Hisaki continuously monitored Jupiter ’ s aurora and plasma torus from 21 January to 30 August 2016 (day of year, DOY, 21 – 243). This study de ﬁ nes the analysis period from DOY136 to 160, which overlaps the HST observations investigated by Nichols et al. . The continuous monitoring was made with the extreme ultraviolet (EUV) spectrometer, EXCEED, on board Hisaki [Yoshioka et al., 2013; Yamazaki et al., 2014]. The EUV photons emitted from the aurora and torus mea- sured with EXCEED are reduced to spectral imaging data. In the observation period of the present study, the dumbbell ‐ shaped slit was used for imaging spectroscopy (see Figure 1 of Kimura et al. ). The slit length along the spatial axis is 360 arcsec, while its width along the wavelength axis is 140 arcsec, narrowed to 20 arc- sec at ±45 arcsec from the middle point of the spatial axis. The spectral range spans from 550 to 1450 Å with a resolution of 3 Å full width at half maximum (FWHM). The FWHM of the point spread function (PSF) is ~17 arcsec [Yamazaki et al., 2014; Yoshioka et al., 2013]. Hisaki continuously acquired the imaging spectra during 40 – 60 min of every 100 min Hisaki orbit. This data acquisition continued through DOY21 – 243. Following Kimura et al. [2015, 2016], the power emitted from the aurora is derived by 10 min integration of the imaging spectral data. The spectral region used for the integration spans from 900 to 1480 Å, and the spatial region of 20 arcsec from Jupiter ’ s north pole is extracted. The contamination by disk emission was estimated to be ~150 GW when the northern aurora faces antiearthward [Kimura et al., 2015].