In this work, North American Aerospace Defense Command (NORAD) tracking of the SpaceX Starlink satellite launch on 3 February 2022 is reviewed. Of the 49 Starlink satellites released into orbit, 38 were eventually lost. A total of 32 of the satellites were never tracked by NORAD. Two different physical mechanisms have been proposed and published in Space Weather to explain the satellite losses, while another mechanism has been proposed in a publication archived on arXiv. It is argued that none of these three papers can explain the immediate loss of 32 of the 49 satellites. We suggest that scientists use NORAD satellite tracking information to further investigate possible loss mechanisms.

Substorms and strong convection events occurring during high-intensity long-duration continuous auroral electrojet (AE) activity (HILDCAA) events are associated with acceleration of magnetospheric relativistic electrons. From an analysis of Van Allen Probe satellite measurements, it is shown that ~7 MeV electrons are accelerated during ~3.4–4.1 days-long HILDCAA events. The dominant acceleration process is due to wave-particle interactions between magnetospheric electromagnetic chorus waves and substorm injected ~100 keV electrons. The longer the HILDCAA and chorus last, the higher the maximum energy of the accelerated relativistic electrons. The acceleration to higher and higher energies is by a bootstrap mechanism. Due to the unusually long process associated with the electron acceleration to ~7 MeV, spacecraft controllers can be given proper advance warning to shift to other modes of operation for the protection of spacecraft electronics.

A comprehensive theoretical model for a homogeneous plasma system of hot, tenuous Maxwellian ring-distributed protons and the cold background of Maxwellian ions and electrons is used to study the resonant instabilities of magnetosonic (MS) waves. The perpendicular velocity integrals associated with the Maxwellian ring distribution have no analytical solution, hence, are solved numerically, while the parallel velocity integrals are solved analytically by invoking series expansion of the plasma dispersion function. For the plasma parameters relevant to Earth’s inner magnetosphere, the theoretical model generates MS waves with frequencies from 5 times the local proton cyclotron frequency to above the lower hybrid frequency for a propagation angle of 89.5°. Hydrogen (H ^+ ) band electromagnetic ion cyclotron waves are also excited by the Maxwellian ring protons for the same set of plasma parameters. A detailed analysis reveals that a sufficiently large ring velocity, as well as a smaller perpendicular and parallel thermal velocity, can enhance the MS wave growth. The study also explores the role of background plasma parameters in modulating the waves. The present theoretical model reproduces the harmonics of the MS waves observed by the Van Allen Probes in the Earth’s inner magnetosphere. Further, the model can generate MS waves in other plasma environments, e.g., Mars, where the presence of ring protons has been established by MAVEN in connection with the MS wave observations.

Magnetospheric relativistic electrons are accelerated during substorms and strong convection events that occur during high-intensity long-duration continuous auroral electrojet activity (HILDCAA) events, associated with solar wind high-speed streams (coming from coronal holes). From an analysis of ∼2–20 MeV electrons at L ∼ 2–7 measured by the Van Allen Probe satellite, it is shown that ∼3.4–4.1 days long HILDCAA events are characterized by ∼7.2 MeV electron acceleration in the L ∼ 4.0–6.0 region, which occurs ∼2.9–3.4 days after the onset of HILDCAA. The dominant acceleration process is due to wave–particle interactions between magnetospheric electromagnetic chorus waves and substorm-injected ∼100 keV electrons. The longer the HILDCAA and chorus last, the higher the maximum energy of the accelerated relativistic electrons. The acceleration to higher and higher energies is due to a bootstrap mechanism.

The 6-7 April 2000 superstorm of SYM-H intensity = -319 nT discussed in Meng et al. (2019; ) was misidentified as being due to an interplanetary coronal mass ejection associated with a solar flare. The interplanetary cause was a highly unusual corotating interaction region (CIR) bounded by a strong fast forward shock (FS) with magnetosonic Mach number Mms = 4.6 and a fast reverse shock (RS) with Mms = 1.9. The exceptionally strong FS caused a similar to 3-factor interplanetary magnetic field (IMF) magnitude amplification in the leading half of the CIR with peak southward IMF Bz = -27 nT causing the superstorm. A plasma region between a tangential discontinuity and the stream interface had a scale size of similar to 0.096 AU. We hypothesize that this is the first detection of a coronal jet at 1 AU. The jet/Gold magnetic tongue (1959; ) was embedded within the CIR, contained the southward Bz and caused the magnetic storm. We hypothesize that a shrinking coronal hole and magnetic reconnection caused the formation and release of the jet.

The recent superstorm of 2024 May 10-11 is the second largest geomagnetic storm in the space age and the only one that has simultaneous interplanetary data (there were no interplanetary data for the 1989 March storm). The May superstorm was characterized by a sudden impulse (SI+) amplitude of +88 nT, followed by a three-step storm main-phase development, which had a total duration of similar to 9 hr. The cause of the first storm main phase with a peak SYM-H intensity of -183 nT was a fast-forward interplanetary shock (magnetosonic Mach number M ms similar to 7.2) and an interplanetary sheath with a southward interplanetary magnetic field component B s of similar to 40 nT. The cause of the second storm's main phase with an SYM-H intensity of -354 nT was a deepening of the sheath B s to similar to 43 nT. A magnetosonic wave (M ms similar to 0.6) compressed the sheath to a high magnetic field strength of similar to 71 nT. Intensified B s of similar to 48 nT were the cause of the third and most intense storm main phase, with an SYM-H intensity of -518 nT. Three magnetic cloud events with B s fields of similar to 25-40 nT occurred in the storm recovery phase, lengthening the recovery to similar to 2.8 days. At geosynchronous orbit, similar to 76 keV to similar to 1.5 MeV electrons exhibited similar to 1-3 orders of magnitude flux decreases following the shock/sheath impingement onto the magnetosphere. The cosmic-ray decreases at Dome C, Antarctica (effective vertical cutoff rigidity <0.01 GV) and Oulu, Finland (rigidity similar to 0.8 GV) were similar to 17% and similar to 11%, respectively, relative to quiet-time values. Strong ionospheric current flows resulted in extreme geomagnetically induced currents of similar to 30-40 A in the subauroral region. The storm period is characterized by strong polar-region field-aligned currents, with similar to 10 times intensification during the main phase and equatorward expansion down to similar to 50 degrees geomagnetic (altitude-adjusted) latitude.

In 1980, Prof. Bimla Buti derived, for the first time, an exact solution for localized nonlinear ion-acoustic waves in a plasma with two electron components. Her theory predicted that in the presence of a second electron component, ion-acoustic holes (i.e., solitons with density dips) can exist in addition to regular ion-acoustic solitons having density humps. In 1982, Temerin, et al. [1] reported the observations of ion holes in the Earth’s auroral acceleration region between 6000 and 8000 km altitude by S3-3 spacecraft, thus confirming the theoretical predictions of Buti’s model. Later on, ion holes were observed on auroral field lines by the Viking spacecraft [2,3] and the Polar spacecraft [4]. It is indeed a nice example where theory leads space experiments and observations.

Updated summaries of the August 1972 and March 1989 space weather events have been constructed. The features of these two events are compared to the Carrington 1859 event and a few other major space weather events. It is concluded that solar active regions release energy in a variety of forms (X-rays, EUV photons, visible light, coronal mass ejection (CME) plasmas and fields) and they in turn can produce other energetic effects (solar energetic particles (SEPs), magnetic storms) in a variety of ways. It is clear that there is no strong one-to-one relationship between these various energy sinks. The energy is often distributed differently from one space weather event to the next. Concerning SEPs accelerated at interplanetary CME (ICME) shocks, it is concluded that the Fermi mechanism associated with quasi-parallel shocks is relatively weak and that the gradient drift mechanism (electric fields) at quasi-perpendicular shocks will produce harder spectra and higher fluxes. If the 4 August 1972 intrinsic magnetic cloud condition (southward interplanetary magnetic field instead of northward) and the interplanetary Sun to 1 au conditions were different, a 4 August 1972 magnetic storm and magnetospheric dawn-to-dusk electric fields substantially larger than the Carrington event would have occurred. Under these special interplanetary conditions, a Miyake et al. (2012), -like extreme SEP event may have been formed. The long duration complex 1989 storm was probably greater than the Carrington storm in the sense that the total ring current particle energy was larger. All the main information for the August 1972 and March 1989 space weather events have been gathered together for the readership. Various features of these two events have been compared and contrasted to the Carrington event and several other recent major events. It is thought that major energetic MeV to GeV particle acceleration occurs at interplanetary shocks instead of acceleration at the solar flare site. Two popular mechanisms for shock particle acceleration are: (a) Fermi acceleration between waves upstream and downstream of a shock, and (b) particle gradient drift in the direction of an electric field along the shock surface. The second mechanism is concluded to form a harder particle spectrum with higher fluxes. If the intrinsic conditions of the 4 August 1972 coronal mass ejection were different (southward interplanetary magnetic fields) and that propagated to the Earth without major evolution or distortion, a magnetic storm equal to or more intense than the Carrington event would have occurred. We have also constructed a scenario involving altered interplanetary space for the August 1972 event which could lead to a high Mach number quasiperpendicular shock and possibly a solar particle event comparable to the Miyake et al. (2012, ) tree ring event. The August 1972 and March 1989 space weather events are summarized and compared to the Carrington plus a few other recent events With different solar and interplanetary conditions, the August 1972 ICME could have caused a storm greater than the Carrington storm The complex March 1989 storm was a "stealth magnetic storm", probably greater ring-current energy-wise than the Carrington storm

The 23-24 April 2023 double-peak (SYM-H intensities of -179 and -233 nT) intense geomagnetic storm was caused by interplanetary magnetic field southward component Bs associated with an interplanetary fast-forward shock-preceded sheath (Bs of 25 nT), followed by a magnetic cloud (MC) (Bs of 33 nT), respectively. These interplanetary structures were led by a coronal mass ejection erupted from the Sun in association with an M1.7 X-ray flare. At the center of the MC, the plasma density exhibited an order of magnitude decrease, leading to a sub-Alfv & eacute;nic solar wind interval for similar to 2.1 hr. Ionospheric Joule heating accounted for a significant part (similar to 81%) of the magnetospheric energy dissipation during the storm main phase. Equal amount of Joule heating in the dayside and nightside ionosphere is consistent with the observed intense and global-scale DP2 (disturbance polar) currents during the storm main phase. The sub-Alfv & eacute;nic solar wind is associated with disappearance of substorms, a sharp decrease in Joule heating dissipation, and reduction in electromagnetic ion cyclotron wave amplitude. The shock/sheath compression of the magnetosphere led to relativistic electron flux losses in the outer radiation belt between L* = 3.5 and 5.5. Relativistic electron flux enhancements were detected in the lower L* <= 3.5 region during the storm main and recovery phases. Equatorial ionospheric plasma anomaly structures are found to be modulated by the prompt penetration electric fields. Around the anomaly crests, plasma density at similar to 470 km altitude and altitude-integrated ionospheric total electron content are found to increase by similar to 60% and similar to 80%, with similar to 33% and similar to 67% increases in their latitudinal extents compared to their quiet-time values, respectively. A fast interplanetary coronal mass ejection (ICME) and its upstream sheath caused severe disturbances in the Earth's magnetosphere during 23-24 April 2023. The sheath anti-sunward of the fast ICME shock was composed of high-density plasmas and intense magnetic fields. This was followed by a plasma density rarefaction and intense magnetic fields with a field rotation (known as a magnetic cloud). This complex interplanetary structure resulted in a double-peak geomagnetic storm, and several intense auroral substorms. Solar wind kinetic energy transferred into the magnetosphere during the geomagnetic storm caused large Joule heating in the auroral ionosphere in both dayside and nightside of Earth. Compression of the magnetosphere by the shock/sheath caused losses of relativistic-energy electrons from the outer radiation belt at the beginning of the magnetospheric event. The equatorial ionospheric anomaly structure, characterized by a low plasma region on the geomagnetic equator and plasma enhancements on both sides (similar to +/- 10 degrees) of the equator, was significantly altered during the magnetic storm. In particular, the plasma density crests were more intense and expanded in hemispherical distribution. These variations are attributed to the prompt penetration electric fields to the equatorial ionosphere, which in turn modulated the equatorial ionospheric dynamics. These results should be important for prediction and modeling of geomagnetic storms and their impacts. The April 2023 double-peak geomagnetic storm is a classic event with a sub-Alfv & eacute;nic region located in the middle of a magnetic cloud Relativistic electrons displayed classic flux variations and dayside/nightside Joule heating was the dominant storm energy dissipation The near-equatorial ionospheric plasma responded to a prompt penetration electric field

An analysis of the Magnetospheric Multiscale (MMS) spacecraft data shows the presence of slow electrostatic solitary waves (SESWs) in the Earth’s plasma sheet, which have been interpreted as slow electron holes (SEHs). An alternative mechanism based on slow ion-acoustic solitons is proposed for these SESWs. The SESWs are observed in the region where double humped ion distributions and hot electrons co-exist. Our theoretical model considers the plasma in the SESW region to consist of hot electrons with a vortex distribution, core Maxwellian protons drifting parallel to the magnetic field, B and beam protons drifting anti-parallel to B. Parallel propagating nonlinear ion-acoustic waves are studied using the Sagdeev pseudopotential technique. The analysis yields four types of modes, namely, two slow ion-acoustic (SIA1 and SIA2) solitons and two fast ion-acoustic (FIA1 and FIA2) solitons. All solitons have positive potentials. Except the FIA1 solitons which propagate parallel to B; the other three types propagate anti-parallel to B. Good agreement is found between the amplitudes of electrostatic potential, the electric field, the widths and speed of SIA1 and SIA2 solitons, and the observed properties of SESWs by the MMS spacecraft.

We analyzed intense geomagnetically induced currents (GICs) recorded during a complex space weather event observed on 23-24 April 2023. Two geomagnetic storms characterized by SYM/H intensities of -179 nT and -233 nT were caused by southward interplanetary magnetic field (IMF) Bz component of -25 nT in the sheath fields, and -33 nT in the magnetic cloud (MC) fields, respectively. GIC observations were divided into two local time sectors: nighttime (1700-2400 UT on 23 April) GICs observed during the interplanetary sheath magnetic storm, and morning sector (0200-0700 UT on 24 April) GICs observed during the MC magnetic storm. By using the direct measurements of GICs on several substations of Karelian-Kola power line (located in the north-west portion of Russia) and gas pipeline station near Mantsala (south of Finland), we managed to trace the meridional profile of GIC increases at different latitudes. It was shown that the night sector GIC intensifications (similar to 18-42 A) occurred in accordance with poleward expansion of the westward electrojet during a substorm. On the other hand, the intense morning sector GICs (similar to 12-46 A) were caused by Ps 6 magnetic pulsations. In addition, a strong local morning GIC (similar to 44 A) was associated with a local substorm-like disturbance caused by a high-density solar wind structure, possibly a coronal loop portion of an interplanetary coronal mass ejection.

We report observations of co-existing rising and falling tone emissions of Electromagnetic Ion Cyclotron (EMIC) waves by THEMIS E spacecraft. The investigation of these fine structures of the EMIC waves is essential from the point of view of understanding the connection between the proton holes and the proton hills in velocity phase-space. The wave packets of rising and falling tones are tracked by Poynting vector analysis, where we observe that the rising tones are propagating northward and the falling tones are propagating southward. The nonlinear wave growth theory supports our observations. We propose a model where the proton velocity distribution function evolves through the formation of proton holes on the negative side of the distribution function and mirrored resonant protons forming proton hills on the positive side of the distribution function, allowing us to observe the co-existing rising and falling tone EMIC waves.

A comparative analysis is carried out between the ion beam and velocity shear as the possible source of free energy in the generation of kinetic Alfvén waves (KAWs) through a three-component theoretical model. The model consists of Kappa electrons, Maxwellian background ions, and drifting-Maxwellian beam ions as the constituent species. The ion beam and velocity shear-driven resonant instabilities of KAWs are investigated and the results are compared on a one-to-one basis. In the presence of κ-electrons, velocity shear is found to be a more effective source of free energy as compared to ion beam in the generation of KAWs. The threshold value of both energy sources in the excitation of KAWs is found numerically for a fixed set of plasma parameters. The characteristics of KAWs such as real frequency, parallel and perpendicular wavelength range, wave unstable region, growth rate, etc. are examined for both cases and the results are compared with the observed values relevant to Earth’s magnetotail.

Large amplitude parallel propagating electric field structures of nonlinear electron-acoustic waves are examined in an unmagnetized magnetosheath plasma. Based on the observations and simulations by Ergun et al. (2016), the plasma in the magnetosheath side of the ion diffusion layer is modeled by a 3-component adiabatic fluid dynamic plasma consisting of cold magnetospheric (MSP) electrons, magnetosheath electrons, and background ions. Using the Sagdeev pseudopotential technique, for the plasma parameters recorded by the Magnetospheric Multiscale (MMS) mission in the magnetosheath side of the ion diffusion region, existence regime of the nonlinear electrostatic solitary wave structures is obtained with the possibilities of stopbands (forbidden gap region). Stopbands or the forbidden gap region exists even when the drift velocity of the cold electron beam is zero. The forbidden gap region becomes wider and the Mach numbers of the regions supporting solitary structures become larger by an increase in the drift velocity of the cold electron beam. The results are in agreement with the magnetosheath electrostatic waves having amplitudes of 100s mV/m and frequencies up to 3.2 kHz observed by the MMS.

Large-amplitude electrostatic waves propagating parallel to the background magnetic field have been observed at the Earth’s magnetopause by the Magnetospheric Multiscale (MMS) spacecraft. These waves are observed in the region where there is an intermixing of magnetosheath and magnetospheric plasmas. The plasma in the intermixing region is modeled as a five-component plasma consisting of three types of electrons, namely, two counterstreaming hot electron beams and cold electrons, and two types of ions, namely, cold background protons and a hot proton beam. Sagdeev pseudo-potential technique is used to study the parallel propagating nonlinear electrostatic solitary structures. The model predicts four types of modes, namely, slow ion-acoustic mode, fast ion-acoustic mode, slow electron-acoustic mode and fast electron-acoustic modes. Except the fast ion-acoustic mode, all other modes support solitons. Whereas slow ion-acoustic solitons have positive potentials, both slow and fast electron-acoustic solitons have negative potentials. For the case of 4% cold electron density, the slow ion-acoustic solitons have electric field ∼(40–120) mV m−1. The fast Fourier transforms (FFT) of slow ion-acoustic solitons produce broadband frequency spectra having peaks between ∼100 Hz to 1000 Hz. These theoretical predictions are in good agreement with the observations. The slow and fast electron-acoustic solitons could be relevant in explaining the low-intensity high (>1 kHz) frequency waves which are also observed at the same time.

Kinetic theory of low frequency electrostatic waves is carried out in the lunar wake plasma modelled by kappa electrons, kappa-beam electrons, Maxwell–Boltzmann distributed protons and doubly charged Helium ions. The present work is motivated by observation of electrostatic waves on the outbound side of the first lunar wake flyby of the mission Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's Interaction with the Sun (ARTEMIS) probe P1. The dispersion characteristics of electrostatic waves which are identified as ion-acoustic waves are carried out for the observational plasma parameters. The frequencies of the ion acoustic waves derived from the model corresponding to peak growth rates are f⩽0.02fpe; (fpe being electron plasma frequency) which matches with the frequency of the waves observed by wave burst 1 (WB1) in the lunar wake (Tao et al., 2012). Our theoretical analysis reveals that in order to excite the low-frequency wave modes, low-energy electron beams are required which are not apparent in the observations.

Kinetic dispersion of the ion acoustic waves has been explored for an unmagnetized five component plasma system comprising of Venusian protons, Venusian oxygen ions, Venusian electrons, solar wind protons, and kappa electrons. The solar wind protons and electrons are assumed to be streaming along the ambient magnetic field. The plasma parameters for this study have been obtained from Lundin et al. [Icarus 215(2), 751–758 (2011)] for the dawn dusk meridian of Venus Express with the data from the ASPERA-4 ion mass analyzer. Our analysis revealed that two modes, viz., ion acoustic mode and beam driven mode, are excited for the considered plasma parameters. The ion acoustic mode exists due to the Venusian ions, and its growth rate is influenced by the solar wind beam electrons. The beam driven mode's existence and its growth rate depend on the solar wind beam protons. We conjecture that the ion acoustic mode and the beam driven mode could be useful in explaining the electrostatic noise in the Venusian ionosphere in the range of several hundreds Hz to 1 kHz and several tens kHz, respectively.

The Helios 1 (H1) and Helios 2 (H2) spacecraft measured the solar winds at a distance between ∼0.3 and 1.0 au from the Sun. With increasing heliocentric distance ( r h ), the plasma speed is found to increase at ∼34–40 km s −1 au −1 and the density exhibits a sharper fall ( r h − 2 ) compared to the magnetic field magnitude ( r h − 1.5 ) and the temperature ( r h − 0.8 ). Using all available solar wind plasma and magnetic field measurements, we identified 68 and 39 fast interplanetary shocks encountered by H1 and H2, respectively. The overwhelming majority (85%) of the shocks are found to be driven by interplanetary coronal mass ejections (ICMEs). While the two spacecraft encountered more than 73 solar wind high-speed streams (HSSs), only ∼22% had shocks at the boundaries of corotating interaction regions (CIRs) formed by the HSSs. All of the ICME shocks were found to be fast forward (FF) shocks; only four of the CIR shocks were fast reverse shocks. Among all ICME FF shocks (CIR FF shocks), 60% (75%) are quasi-perpendicular with shock normal angles ( θ Bn ) ≥ 45° relative to the upstream ambient magnetic field, and 40% (25%) are quasi-parallel ( θ Bn < 45°). No radial dependences were found in FF shock normal angle and speed. The FF shock Mach number ( M ms ), magnetic field, and plasma compression ratios are found to increase with increasing r h at the rates of 0.72, 0.89, and 0.98 au −1 , respectively. On average, ICME FF shocks are found to be considerably faster (∼20%) and stronger (with ∼28% higher M ms ) than CIR FF shocks.

The Colaba, India ~-1600 nT magnetic spike caused by an interplanetary sheath magnetic field inducing a "dayside R1-field aligned current wedge" during the Carrington magnetic storm proposed by Ohtani (2022, https://doi.org/10.1029/2022JA030596) seems highly improbable. Normal interplanetary magnetic field intensities of ~5 nT have previously been shown to be sufficient to explain the ~+120 nT SI+ observed at Colaba during the storm (Tsurutani et al., 2018, https://doi.org/10.1002/2017JA024779). Magnetohydrodynamic theory (Kennel et al., 1985, https://doi.org/10.1029/GM034p0001) predicts a maximum of 4x magnetic field compression by a fast shock, giving an interplanetary sheath field of ~20 nT, a value too low to support the Ohtani (2022) hypothesis. The Ohtani (2022) (and Siscoe et al. 2006, https://doi.org/10.1016/j.asr.2005.02.102) claim of a further 10x amplification of the interplanetary sheath fields has not been verified in near-Earth interplanetary sheaths. The original (Tsurutani et al., 2003, https://doi.org/10.1029/2002JA009504) hypothesis that an ICME magnetic cloud having southward magnetic fields of ~90 nT caused the Carrington magnetic storm main phase of peak SYM-H/Dst = -1760 nT seems more likely. The short time between the SI+ and the storm main phase onset implies a foreshortened interplanetary sheath. The extremely rapid recovery of the magnetic storm was hypothesized by Tsurutani et al. (2018, https://doi.org/10.1002/2017JA024779) as being due to nonlinear ring current losses. We point out that the Hydro-Quebec 1989 storm was caused by multiple shock-sheaths and magnetic clouds (Lakhina & Tsurutani, 2016, https://doi.org/10.1186/s40562-016-0037-4) unlike the interplanetary causes of the Carrington storm. The Hydro-Quebec event was a "stealth" magnetic storm.

Electrostatic solitary waves (ESWs) in the Venusian ionosphere that are impinged by the solar wind are investigated using a homogeneous, collisionless, and magnetized multicomponent plasma consisting of Venusian H + and O + ions, Maxwellian Venusian electrons and streaming solar wind protons, and suprathermal electrons following κ − distribution. The model supports the propagation of positive potential slow O + and H + ion-acoustic solitons. The evolution and properties of the solitons occurring in two sectors, viz., dawn-dusk and noon-midnight sector of the Venus ionosphere at an altitude of (200–2000) km, are studied. The theoretical model predicts positive potential solitons with amplitude ∼(0.067–56) mV, width ∼(1.7–53.21) m, and velocity ∼(1.48–8.33) km s −1 . The bipolar soliton electric field has amplitude ∼(0.03–27.67) mV m −1 with time duration ∼(0.34–22) ms. These bipolar electric field pulses when Fourier transformed to the frequency domain occur as a broadband electrostatic noise, with frequency varying in the range of ∼9.78 Hz–8.77 kHz. Our results can explain the observed electrostatic waves in the frequency range of 100 Hz–5.4 kHz in the Venus ionosphere by the Pioneer Venus Orbiter mission. The model can also be relevant in explaining the recent observation of ESWs in the Venus magnetosheath by the Solar Orbiter during its first gravity assist maneuver of Venus.