Jupiter Research Articles

The Neutral Water Torus of Europa

AbstractThe neutral particles that escape Europa form a neutral torus which asymmetrically encircles the giant planet Jupiter. The study of this structure can inform on neutral escape at the icy moon and on the loading of the Jovian magnetosphere with Europan material. In this letter, we present the first Monte Carlo model of the neutral water torus of Europa. Water molecules are released to high altitude by ion sputtering of the surface and get dissociated and ionized mostly by electron impact. We find that the density of H2O molecules can be as large as atomic O in a large region of the Jovian magnetosphere. The neutral torus of Europa may therefore have a more diverse composition than previously thought. Plasma instrumentation able to separate H2O+ from O+ pick‐up ions could help to advance our understanding of the neutral torus of Europa.

ExoLyn: A golden mean approach to multispecies cloud modeling in atmospheric retrieval

Clouds are ubiquitous in exoplanets' atmospheres and play an important role in setting the opacity and chemical inventory of the atmosphere. Understanding clouds is a critical step in interpreting exoplanets' spectroscopic data. The aim is to model the multispecies nature of clouds in atmospheric retrieval studies. To this end, we developed -- a 1D cloud model that balances physical consistency with computational efficiency. solves the transport equation of cloud particles and vapor under cloud condensation rates that are self-consistently calculated from thermodynamics. is a standalone, open source package capable of being combined with optool to calculate solid opacities and with petitRADTRANS to generate transmission or emission spectra. With we find that the compositional structure of clouds in hot Jupiter planets' atmospheres is layered with a cloud dominated by magnesiumsilicates on top of an iron cloud. This finding is consistent with more complex cloud formation models but can be obtained with in only a few seconds. The composition of the cloud particles can be constrained from the spectrum, for example MgSiO3 and Mg2SiO4 components give rise to an absorption feature at $8-10\ m $. We investigate the dependence of the cloud structure on the bulk elemental composition of the planet and find that SiO2 -dominated clouds form on metal-rich planets and Fe clouds with a strong extinction effect form on C-rich planets. Designed toward maximum flexibility can also be used in retrieval analysis of sub-Neptunes and self-luminous planets. The efficiency of opens the possibility of joint retrieval of exoplanets' gas and cloud components.

Tracking Advanced Planetary Systems (TAPAS) with HARPS-N

Aims. The star HD 118203, classified as a K0 subgiant, was known to harbour a transiting hot Jupiter planet on a 6.1-day eccentric orbit. Previous studies also revealed a linear trend in the radial velocity (RV) domain, indicative of a companion on a wide orbit. Such a hierarchical orbital architecture could be helpful in studies of the origins of hot Jupiters. Methods. We acquired precise RV measurements over 17 yr using the 9.2 m Hobby-Eberly Telescope and the 3.6 m Telescopio Nazionale Galileo. Combining these observations with space-born photometric time series from the Transiting Exoplanet Survey Satellite, we constructed a two-planetary model for the system. Astrometric observations from HIPPARCOS and Gaia were used to constrain the orbital inclination of the wide-orbit companion and its mass. Numerical simulations were used to investigate the dynamics of the system. The photometric data were searched for additional transit-like flux drops. Results. We found that the additional companion is an 11-Jupiter mass planet orbiting HD 118203 on a 14-yr moderately eccentric orbit, constituting a hierarchical planetary system with the hot Jupiter. Both planets were found to be dynamically decoupled mainly due to the general relativistic apsidal precession of the inner planet, marginalising secular interactions. The orbits of both planets might have a relatively low mutual inclination unless the longitudes of the ascending node differ substantially. This configuration favours the coplanar high-eccentricity migration as a path to the present-day orbital configuration. No other transiting planets with radii down to 2 Earth radii and orbital periods less than 100 days were found in the system.

LONEStar: The Lunar Flashlight Optical Navigation Experiment

This paper documents the results from the highly successful Lunar flashlight Optical Navigation Experiment with a Star tracker (LONEStar). Launched in December 2022, Lunar Flashlight (LF) was a NASA-funded technology demonstration mission. After a propulsion system anomaly prevented capture in lunar orbit, LF was ejected from the Earth-Moon system and into heliocentric space. NASA subsequently transferred ownership of LF to Georgia Tech to conduct an unfunded extended mission to demonstrate further advanced technology objectives, including LONEStar. From August to December 2023, the LONEStar team performed on-orbit calibration of the optical instrument and a number of different OPNAV experiments. This campaign included the processing of nearly 400 images of star fields, Earth and Moon, and four other planets (Mercury, Mars, Jupiter, and Saturn). LONEStar provided the first on-orbit demonstrations of heliocentric navigation using only optical observations of planets. Of special note is the successful in-flight demonstration of (1) instantaneous triangulation with simultaneous sightings of two planets with the LOST algorithm and (2) dynamic triangulation with sequential sightings of multiple planets.

Coma and tail of Comet 67P/Churyumov–Gerasimenko during the 2021–2022 apparition

ABSTRACT We present results on the global activity of comet 67P/Churyumov–Gerasimenko (67P), the ROSETTA target, during its first perihelion passage after the mission and after an encounter with planet Jupiter. 67P was observed by broad-band filter imaging at 33 epochs during 2021 May 21 to 2022 June 1. The mean radial flux profiles suggest that ‘equilibrium’ conditions for the dust flow in the coma existed from around perihelion until about 100 d thereafter. We propose a scenario for the smaller and larger radial exponents, measured before and after the ‘equilibrium’ phase. Four coma fans with possible source regions at +40°, –10°, –50°, and –70° latitude on the nucleus are identified. The three fans at southern latitudes may be identical with fan sources seen during post-perihelion in 2015–2016. The rotation axis of 67P may not have changed at all or at least not much (<5°) from the orientation measured during the Rosetta mission at the comet. The dust streamers in the coma originated from observed coma fans, containing mostly dust emitted within days to weeks before observation. Two dust streamers, a long- and a short-lasting one, contained heavy dust grains from emission periods hundreds of days before perihelion. Similar emission periods are obtained for the dust seen in the tail region of the comet. Similarities and differences in the dust activity during the recent apparition with that of the Rosetta mission at the comet are found.

An approach for end-to-end optimization of low-thrust interplanetary trajectories using collinear libration points

This article presents an approach to solve the problem of end-to-end optimization of the low-thrust interplanetary trajectory. At first, the problem of optimizing low-thrust interplanetary trajectory, which passes through the collinear libration points near the planets of departure and arrival is considered. The obtained solutions from this problem can be used as an initial guess to solve the end-to-end optimization problem, i.e., to calculate interplanetary low-thrust trajectories that satisfy the necessary optimality conditions at the match points of the heliocentric and planetocentric segments of trajectory. The minimum-fuel problem is considered. An indirect method based on the maximum principle, and the continuation method is applied to optimize interplanetary spacecraft trajectories. Numerical examples of trajectories from the Earth orbit to the orbit around the destination planet (Mars and Jupiter) are given. The possibility of a significant reduction in the required characteristic velocity is shown in comparison with the estimates obtained by using the zero-radius sphere of influence model.

Forming Mercury from Excited Initial Conditions

Mercury is notoriously difficult to form in Solar System simulations, due to its small mass and iron-rich composition. Smooth particle hydrodynamics simulations of collisions have found that a Mercury-like body could be formed by one or multiple giant impacts, but due to the chaotic nature of collisions, it is difficult to create a scenario where such impacts will take place. Recent work has found more success forming Mercury analogues by adding additional embryos near Mercury’s orbit. In this work, we aim to form Mercury by simulating the formation of the Solar System in the presence of the giant planets Jupiter and Saturn. We test out the effect of an inner disk of embryos added on to the commonly used narrow annulus of initial material. We form Mercury analogues with core-mass fractions (CMFs) > 0.4 in ∼10% of our simulations, and twice that number of Mercury analogues form during the formation process but are unstable and do not last to the end of the simulations. Mercury analogues form at similar rates for both disks with and without an inner component, and most of our Mercury analogues have lower CMFs than that of Mercury, ∼0.7, due to significant accretion of debris material. We suggest that a more in-depth understanding of the fraction of debris mass that is lost to collisional grinding is necessary to understand Mercury’s formation, or some additional mechanism is required to stop this debris from accreting.

The Newton-Stefan-Boltzmann-Planck Code. The Solar Microwave Background Formation on the Blackbody Sphere at the Distance R = 140 AU

In this model the Solar System presented to observers on the planet Earth the elegant gift: the Solar Microwave Background (SMB) formed on the Blackbody Sphere at the distance R = 140 AU. The thermalization of the Hydrogen wall at this distance was described using the Stefan-Boltzmann law where the temperature of the blackbody at the distance R = 1 AU is T = 393.6 K. Newton’s cooling law described the cooling of this blackbody surface temperature with the cooling constant κ = 1.139 × 10−4 s−1 calculated from data of the small planet Pluto (average distance R = 39.5 AU and the temperature T = 44 K). The SMB monopole temperature T = 2.7255 K was fitted for the distance R = 140 AU with the temperature of the surrounding TENV = 2.5887 K. The first important difference with the model of the cosmic microwave background (CMB) is the magnitude and direction of Newton’s dipole v = (200 + 141) kms−1 towards the galactic coordinates (l, b) = (84°, −48°) while the magnitude and the direction of the Doppler’s dipole of CMB is v = 368 kms−1 towards (l, b) = (264°, 48°). This new model enables to estimate the rotation velocity of the Sun in the Milky Way Galaxy, the motion of the Milky Way Galaxy through the Universe, and the Harress-Sagnac color excess: v = 200 + 141 + 27 = 368 kms−1. The total motion of the Milky Way Galaxy through the Universe can be estimated with the knowledge of the Cold Spot direction in the SMB and the motion towards the Galactic South Pole. In this model, the Milky Way Galaxy can avoid collision with the Andromeda Galaxy. The observed quadrupole, octopole, and hemisphere structure of the SMB can be explained as the local motion of the Sun and the Solar axis inclination towards the ecliptic–the Axis of evil should be renamed as the Solar axis bringing to us a good opportunity to discover differences between the SMB and the CMB. The first peak in the power spectrum of the SMB at the distance R = 140 AU is observed from the COBE, WMAP, and PLANCK satellites rotating around the Sun at the distance R = (2×1) AU under the angle θ = 0.818°. The power spectrum observed from the planets Mercury and Jupiter will have different positions of the first and higher peaks. The original Solar signature should be visible as the moving shadows of the Sunspots on the Blackbody Sphere. There were proposed several experiments on how to distinguish between the SMB and the CMB.

Potential signs of life on Europa

This paper discusses the possibility of life on Europa, the moon of Jupiter by analyzing the biological components, energy source, and ocean environment on Europa. The biological components, especially amino acids, have great possibilities of forming or have already existed on Europa since its compositive elements are present and the environment on Europa is very similar to the primitive Earth. Energy sources are expected to come from the hydrothermal vents at the ocean bottom, which are formed by tidal forces and tidal heating. The hydrothermal vents are rich in chemicals and elements and have the possibility of forming lives in the future. The ocean environment is thought to be rich in oxygen, which comes from the planet Jupiter, it is first reflected on the surface of Europa, but later on, transported to the ocean through the ice layer and a lake in between. Furthermore, the freezing point of the ocean might be affected by the fact that it contains salt, but not by the fact that it has very low air pressure. To conclude, there is a great possibility that lives exist on Europa, but it cannot be 100% positive since no specific experiments have been done throughout the research, and there are so many uncertainties in space that have not been discovered yet.

A 1,470-Year Astronomical Cycle and Its Effect on Earth’s Climate

Earth’s millennial climate warming cycle has been studied by scientists for decades, but its cause has been lacking. It warms the Earth for several hundred years and melts some of the ice sheets in Greenland and Antarctica. This analysis found that the cycle is caused by the astronomical conjunction of the planets Jupiter, Saturn and Neptune. The current cycle started warming the Earth in the year 1791 and will probably reach peak temperature in approximately year 2060 at the next Jupiter, Saturn and Neptune conjunction. Then it will cause cooling oscillations for the rest of the cycle when the heat from the cycle is reduced.

Comparative GC-MS Analysis of Phytochemicals from Clitorea ternatea L. (White Flower Variety) Leaves Treated with Planetary Sounds (Planet Earth and Planet Jupiter) and Estimation of Bioactive Compounds

The butterfly pea (Clitoria ternatea L.) is a plant with various potential health benefits due to the presence of many bioactive compounds. The leaves contain triterpenoids, flavonoids, glycosides, and alkaloids. In the present experimental work, the leave extracts treated with planetary sound (Sound of Earth and Sound of Jupiter) classified as Medium-low frequency sound waves (200 Hz to 1 KHz), in methanol were checked for bioactive components through GC-MS and the third set was kept as control. Different bioactive compounds identified, were further estimated by using Lupeol (Merck, India) as an external standard. In compounds common among plants treated with Earth’s sound and control, 3-O-Methyl-d-glucose from plants treated with Earth’s sound was highest at 1.20 PPM. Compounds common among plants treated with Jupiter’s sound and control, 3-Hexenal from plants treated with Jupiter’s sound was found to be highest with 1.87 PPM, Similarly, compounds common among plant’s treated with Earth’s sound and Jupiter’s sound, Gamma sitosterol from leaves of plants treated with Earth’s sound was found to have highest value i.e, 1.27 PPM. Compounds that were common for all the three groups, plants treated with Earth’s sound was found to have increased Squalene with 1.23 PPM. A general trend of phytochemicals from plants treated with planet Earth’s sound had an elevated value. This suggests that the treatment of planet Earth’s sound has tremendous impact on the production of secondary metabolites in the referred species.

Planetary nodes and apses in the Sūrya-Siddhānta

There are a few aspects of Indian astronomy that border on the implausible, and none more so than the nodal and apsidal movements of planetary orbits as specified in the Sūrya-Siddhānta. In this paper we examine some aspects of this data in the light of modern astronomy. Given the very-slow rates of motion specified for these two parameters, we speculate that this data might be heliocentric (as opposed to geocentric), and proceed with that assumption in this paper. It is determined that while this assumption proves true for the outer planets (Mars, Jupiter and Saturn), it does not conform well with the inner planets (Mercury and Venus). It is also determined that while the directions specified in the Sūrya-Siddhānta for these subtle motions are correct, the rates of motion given are slower by a couple orders of magnitude compared to actuality. Further analysis also appears to confirm that the data is genuine, and the epoch of the data is likely many thousands of years old.

A Review of Radio Observations of the Giant Planets: Probing the Composition, Structure, and Dynamics of Their Deep Atmospheres

Radio observations of the atmospheres of the giant planets Jupiter, Saturn, Uranus, and Neptune have provided invaluable constraints on atmospheric dynamics, physics/chemistry, and planet formation theories over the past 70 years. We provide a brief history of these observations, with a focus on recent and state-of-the-art studies. The global circulation patterns, as derived from these data, in combination with observations at UV/visible/near-IR wavelengths and in the thermal infrared, suggest a vertically-stacked pattern of circulation cells in the troposphere, with the top cell similar to the classical picture, overlying cells with the opposite circulation. Data on the planets’ bulk compositions are used to support or disfavor different planet formation scenarios. While heavy element enrichment in the planets favors the core accretion model, we discuss how the observed relative enrichments in volatile species constrain models of the outer proto-planetary disk and ice giant accretion. Radio observations of planets will remain invaluable in the next decades, and we close with some comments on the scientific gain promised by proposed and under-construction radio telescopes.

Dynamics and Stability of the Two-Body Problem with Yukawa Correction to Newton’s Gravity, Revisited and Applied Numerically to the Solar System

In this manuscript, we review the motion of a two-body celestial system (planet–sun) for a Yukawa-type correction on Newton’s gravitational potential using Hamilton’s formulation. We reexamine the stability using the corresponding linearization Jacobian matrix, and verify that the conditions of Bertrand’s theorem are met for radii ≪1015 m, meaning that bound closed orbits are expected. Applied to the solar system, we present the equation of motion of the planet, then solve it both analytically and numerically. Making use of the analytical expression of the orbit, we estimate the Yukawa strength α and find it to be larger than the nominal value (10−8) adopted in previous studies, in that it is of order (α=10−4−10−5) for the terrestrial planets (Mercury, Venus, earth, Mars, and Pluto) and even larger (α=10−3) for the giant planets (Jupiter, Saturn, Uranus, and Neptune). Taking the inputs (rmin,vmas,e) observed by NASA, we analyse the orbits analytically and numerically for both the estimated and nominal values of α and determine the corresponding trajectories. For each obtained orbit, we recalculate the characterizing parameters (rmin,rmax,a,b,e) and compare their values according to the potential (Newton with/without Yukawa correction) and method (analytical and/or numerical) used. When compared to the observational data, we conclude that the path correction due to Yukawa correction is on the order of up to 80 million km (20 million km) as the maximum deviation occurring for Neptune (Pluto) for a nominal (estimated) value of α.

Precise exaltation position of planet Jupiter (Guru) in Lord Sri Rama’s birth chart

Sage Valmiki in Ramayana did not mention the precise exaltation position of Jupiter (Guru), even though it was stated that five planets were in exaltation in Lord Sri Rama’s birth chart. We have analysed ‘Hamsa (Hansa) Yoga’ mentioned in Brihat Parasara Hora Sastra, Sage Valmiki’s description of position of planets in Lord Rama’s birth chart, and compared it with Lord Rama’s characteristics mentioned in Ramayana to conclude precise exaltation position of planet Jupiter (Guru) in Lord Sri Rama’s birth chart.

Are Am stars and hot-Jupiter planets related?

Context. Metallic-lined A stars (Am stars) are often components of short-period binary systems, where tidal interactions would result in low rotational velocities and help to develop the chemical peculiarities observed. However, the origin of single Am stars and Am stars that belong to wide binary systems is unclear. Aims. There is very recent evidence of an Am star hosting a likely synchronized hot brown dwarf (hot BD) and other possible Am stars hosting hot Jupiter planets. Following literature suggestions, we wonder if these hot low-mass companions could play a role in the development of an Am star, that is to say, if they could help to mitigate the “single Am” problem. Methods. We carried out a detailed abundance determination via spectral synthesis of 19 early-type stars hosting hot BDs and hot Jupiter planets, in order to determine the possible presence of Am stars in this sample. The abundances were determined iteratively for 25 different species by fitting synthetic spectra using the SYNTHE program together with local thermodynamic equilibrium (LTE) ATLAS12 model atmospheres. The abundances of C I, O I, and Mg I were corrected by non-LTE effects. The complete chemical patterns of the stars were then compared to those of Am stars and other chemically peculiar stars. Results. We studied a sample of 19 early-type stars, seven of them hosting hot BDs and 12 of them hosting hot Jupiter planets. We detected four Am stars in our sample (KELT-19A, KELT-17, HATS-70, and TOI-503) and two possible Am stars (TOI-681 and HAT-P-69). In particular, we detected the new Am star HATS-70, which hosts a hot BD, and we ruled out this class for the hot Jupiter host, WASP-189. Both stars show a different composition than previously reported. For the first time, we estimated the incidence of Am stars among stars hosting hot BDs (50−75%) and among stars hosting hot Jupiters (20−42%). The incidence of Am stars hosting hot BDs has shown to be higher than the frequency of Am stars in general. This would imply that the presence of hot BDs could play a role in the development of Am stars and possibly help to mitigate the single Am problem, which is different for the case of hot Jupiter planets. Notably, these results also indicate that the search for hot BDs may benefit from the targeting of single Am stars or Am stars in wide binary systems. We encourage the analysis of additional early-type stars hosting hot companions in order to improve the significance of the initial trends found here.

The GAPS Programme at TNG

Aims. We present a novel method for studying the thermal emission of exoplanets as a function of orbital phase at very high spectral resolution, and use it to investigate the climate of the ultra-hot Jupiter KELT-9b. Methods. We combine three nights of HARPS-N and two nights of CARMENES optical spectra, covering orbital phases between quadratures (0.25 < φ < 0.75), when the planet shows its day-side hemisphere with different geometries. We co-add the signal of thousands of Fe I lines through cross-correlation, which we map to a likelihood function. We investigate the phase-dependence of two separate observable quantities, namely (i) the line depths of Fe I and (ii) their Doppler shifts, introducing a new method that exploits the very high spectral resolution of our observations. Results. We confirm a previous detection of Fe I emission, and demonstrate a precision of 0.5 km s−1 on the orbital properties of KELT-9b when combining all nights of observations. By studying the phase-resolved Doppler shift of Fe I lines, we detect an anomaly in the planet's orbital radial velocity well-fitted with a slightly eccentric orbital solution (e = 0.016 ± 0.003, ω = 150−11+13°, 5σ preference). However, we argue that this anomaly is caused by atmospheric circulation patterns, and can be explained if neutral iron gas is advected by day-to-night atmospheric wind flows of the order of a few km s−1. We additionally show that the Fe I emission line depths are symmetric around the substellar point within 10° (2σ), possibly indicating the lack of a large hot-spot offset at the altitude probed by neutral iron emission lines. Finally, we do not obtain a significant preference for models with a strong phase-dependence of the Fe I emission line strength. We show that these results are qualitatively compatible with predictions from general circulation models (GCMs) for ultra-hot Jupiter planets. Conclusions. Very high-resolution spectroscopy phase curves are of sufficient sensitivity to reveal a phase dependence in both the line depths and their Doppler shifts throughout the orbit. They constitute an under-exploited treasure trove of information that is highly complementary to space-based phase curves obtained with HST and JWST, and open a new window onto the still poorly understood climate and atmospheric structure of the hottest planets known to date.

Jupiter's Banding and Jets May Be Caused by Tides

The stratification parameters for Jupiter’s outer 3000 km shell are calculated using a density profile recently derived from observations of the NASA Juno spacecraft currently in Jovian orbit. Using these parameters, the equations of classical tidal theory for a stratified, nonhydrostatic, compressible fluid are numerically solved for sectoral tidal forcing by Io. The results support a long-standing though little discussed proposal that the banding/jets (and possibly the unexplained endogenic heat) are caused by the tides. First, general arguments from eigenmode analyses expect resonantly forced tidal modes and the scattering of the tidal response to higher spatial degrees by Jupiter’s fast rotation, with time-averaged tidal effects appearing in bands between critical latitudes (±50° for forcing by Io). Second, resonant tides and banding are specifically demonstrated in the tidal model configured with the Juno-derived stratification. While banding in the time-averaged tidal features is a robust expectation (from the well-prescribed forcing and rotation parameters) and is independent of the internal parameters, the details of the banding (e.g., number, width) are highly dependent. Hence, comparison of the tidal model with observations provides a test of the tidal hypothesis of the bands as well as assumptions of interior parameters and processes. Here, dissipation parameterized as a simple pressure relaxation term in the vertical balance equation shows a time-mean banded structure between the critical latitudes that can drive geostrophic jets matching the major observed features, including strong prograde flow at the equator. By contrast, alternate stratification/dissipation assumptions produce banded structures that do not agree with observations.

Synchronizing the helicity of Rayleigh–Bénard convection by a tide-like electromagnetic forcing

We present results on the synchronization of the helicity in a liquid-metal Rayleigh–Bénard experiment under the influence of a tide-like electromagnetic forcing with azimuthal wavenumber m = 2. We show that for a critical forcing strength the typical large-scale circulation in the cylindrical vessel of aspect ratio unity is entrained by the period of the tide-like forcing, leading to synchronized helicity oscillations with opposite signs in two half-spaces. The obtained experimental results are consistent with and supported by numerical simulations. A similar entrainment mechanism for the helicity in the solar tachocline may be responsible for the astonishing synchronization of the solar dynamo by the 11.07-year triple synodic alignment cycle of the tidally dominant planets Venus, Earth, and Jupiter.

Tracking extraterrestrial signals using the Super SID and Radio JOVE kits

A 20.1MHz dipole radio telescope was assembled, characterized and tested to detect extraterrestrial signals from planet Jupiter. Two element dipole arrays were built for the detection of 20.1MHz radio emission from the Jupiter-Io interaction, strong solar burst, the galactic background and the transit of the galactic center. Using the specifications and the layout, the dipole array was constructed. The block diagram, the schematic diagram built for NASA was used to solder together the radio frequency band pass filter, audio Preamplifier and audio amplifier to make the radio JOVE receiver. This was characterized, tested and tuned by setting the tuning knob to 20.0MHz. The dipole antenna was connected to the receiver and a variety of radio frequency emissions were detected. These signals were captured on a personal computer via the radio Jupiter Pro 3.8.3 and radio skypipe 2.6.5 software compatible with windows 7 OS and has python programme which converts data from the sod format to ASCII format to conveniently analyzed them. The data locally captured was correlated with other stations of the world. Specifically the analyzed chart of 14th July 2022 shows a lot of similarities with that captured by radio telescope UNIVERSUM shared with the global web repository.