A whistler is a very low frequency (VLF) electromagnetic (radio) wave generated by lightning. Frequencies of terrestrial whistlers are 1 kHz to 30 kHz, with maximum frequencies usually at 3 kHz to 5 kHz. Although they are electromagnetic waves, they occur at audio frequencies, and can be converted to audio using a suitable receiver. They are produced by lightning strikes where the impulse travels along the Earth's magnetic field lines from one hemisphere to the other. They undergo dispersion of several kHz due to the slower velocity of the lower frequencies through the plasma environments of the ionosphere and magnetosphere. Thus they are perceived as a descending tone which can last for a few seconds. The study of whistlers categorizes them into Pure Note, Diffuse, 2-Hop, and Echo Train types.
Helios-A and Helios-B are a pair of probes that were launched into heliocentric orbit to study solar processes. As a joint venture between German Aerospace Center (DLR) and NASA, the probes were launched from Cape Canaveral Air Force Station, Florida, on December 10, 1974, and January 15, 1976, respectively.
IMAGE is a NASA Medium Explorer mission that studied the global response of the Earth's magnetosphere to changes in the solar wind. It was believed lost but as of August 2018 might be recoverable. It was launched 25 March 2000, at 20:34:43.929 UTC, by a Delta II launch vehicle from Vandenberg Air Force Base on a two-year mission. Almost six years later, it unexpectedly ceased operations in December 2005 during its extended mission and was declared lost. The spacecraft was part of NASA's Sun-Earth Connections Program, and its data has been used in over 400 research articles published in peer-reviewed journals. It had special cameras that provided various breakthroughs in understanding the dynamics of plasma around the Earth. The principal investigator was Jim Burch of the Southwest Research Institute.
Juno is a NASA space probe orbiting the planet Jupiter. It was built by Lockheed Martin and is operated by NASA's Jet Propulsion Laboratory. The spacecraft was launched from Cape Canaveral Air Force Station on August 5, 2011 UTC, as part of the New Frontiers program. Juno entered a polar orbit of Jupiter on July 5, 2016, UTC, to begin a scientific investigation of the planet. After completing its mission, Juno will be intentionally deorbited into Jupiter's atmosphere.
The magnetosphere of Saturn is the cavity created in the flow of the solar wind by the planet's internally generated magnetic field. Discovered in 1979 by the Pioneer 11 spacecraft, Saturn's magnetosphere is the second largest of any planet in the Solar System after Jupiter. The magnetopause, the boundary between Saturn's magnetosphere and the solar wind, is located at a distance of about 20 Saturn radii from the planet's center, while its magnetotail stretches hundreds of Saturn radii behind it.
The Global Geospace Science (GGS) Wind satellite is a NASA science spacecraft designed to study radio waves and plasma that occur in the solar wind and in the Earth's magnetosphere. It was launched on 1 November 1994, at 09:31:00 UTC, from launch pad LC-17B at Cape Canaveral Air Force Station (CCAFS) in Merritt Island, Florida, aboard a McDonnell Douglas Delta II 7925-10 rocket. Wind was designed and manufactured by Martin Marietta Astro Space Division in East Windsor Township, New Jersey. The satellite is a spin-stabilized cylindrical satellite with a diameter of 2.4 m and a height of 1.8 m.
Explorer 52, also known as Hawkeye-1, Injun-F, Neutral Point Explorer, IE-D, Ionospheric Explorer-D, was a NASA satellite launched on 3 June 1974, from Vandenberg Air Force Base on a Scout E-1 launch vehicle.
The magnetosphere of Jupiter is the cavity created in the solar wind by Jupiter's magnetic field. Extending up to seven million kilometers in the Sun's direction and almost to the orbit of Saturn in the opposite direction, Jupiter's magnetosphere is the largest and most powerful of any planetary magnetosphere in the Solar System, and by volume the largest known continuous structure in the Solar System after the heliosphere. Wider and flatter than the Earth's magnetosphere, Jupiter's is stronger by an order of magnitude, while its magnetic moment is roughly 18,000 times larger. The existence of Jupiter's magnetic field was first inferred from observations of radio emissions at the end of the 1950s and was directly observed by the Pioneer 10 spacecraft in 1973.
Dynamics Explorer was a NASA mission, launched on 3 August 1981, and terminated on 28 February 1991. It consisted of two unmanned satellites, DE-1 and DE-2, whose purpose was to investigate the interactions between plasmas in the magnetosphere and those in the ionosphere. The two satellites were launched together into polar coplanar orbits, which allowed them to simultaneously observe the upper and lower parts of the atmosphere.
The Jupiter Icy Moons Explorer is an interplanetary spacecraft that was launched on 14 April 2023 from Guiana Space Centre in the French Guiana by the European Space Agency (ESA) with Airbus Defence and Space as the main contractor. The mission is planned to study Ganymede, Callisto, and Europa, three of Jupiter's Galilean moons. They are thought to have significant bodies of liquid water beneath their icy surfaces which would make them potentially habitable environments.
JEDI (Jupiter Energetic-particle Detector Instrument) is an instrument on the Juno spacecraft orbiting planet Jupiter. JEDI coordinates with the several other space physics instruments on the Juno spacecraft to characterize and understand the space environment of Jupiter's polar regions, and specifically to understand the generation of Jupiter's powerful aurora. It is part of a suite of instruments to study the magnetosphere of Jupiter. JEDI consists of three identical detectors that use microchannel plates and foil layers to detect the energy, angle, and types of ion within a certain range. It can detect electrons between 40 and 500 keV (Kilo electron-volts), and hydrogen and oxygen from a few tens of keV to less than 1000 keV (1 MeV). JEDI uses radiation hardened Application Specific Integrated Circuits (ASIC)s. JEDI was turned on in January 2016 while still en route to Jupiter to also study interplanetary space. JEDI uses solid state detectors (SSD's) to measure the total energy (E) of both the ions and the electrons. The MCP anodes and the SSD arrays are configured to determine the directions of arrivals of the incoming charged particles. The instruments also use fast triple coincidence and optimum shielding to suppress penetrating background radiation and incoming UV foreground.
The ISEE-1 was an Explorer-class mother spacecraft, International Sun-Earth Explorer-1, was part of the mother/daughter/heliocentric mission. ISEE-1 was a 340.2 kg (750 lb) space probe used to study magnetic fields near the Earth. ISEE-1 was a spin-stabilized spacecraft and based on the design of the prior IMP series of spacecraft. ISEE-1 and ISEE-2 were launched on 22 October 1977, and they re-entered on 26 September 1987.
The ISEE-2 was an Explorer-class daughter spacecraft, International Sun-Earth Explorer-2, was part of the mother/daughter/heliocentric mission. ISEE-2 was a 165.78 kg (365.5 lb) space probe used to study magnetic fields near the Earth. ISEE-2 was a spin-stabilized spacecraft and based on the design of the prior IMP series of spacecraft. ISEE-1 and ISEE-2 were launched on 22 October 1977, and they re-entered on 26 September 1987.
Jovian Auroral Distributions Experiment (JADE) is an instrument that detects and measures ions and electrons around the spacecraft. It is a suite of detectors on the Juno Jupiter orbiter. JADE includes JADE-E, JADE-I, and the EBox. JADE-E and JADE-I are sensors that are spread out on the spacecraft, and the EBox is located inside the Juno Radiation Vault. EBox stands for Electronics Box. JADE-E is for detecting electrons from 0.1 to 100 keV, and there are three JADE-E sensors on Juno. JADE-I is for detecting ions from 5 eV to 50 keV. It is designed to return data in situ on Jupiter's auroral region and magnetospheric plasmas, by observing electrons and ions in this region. It is primarily focused on Jupiter, but it was turned on in January 2016 while still en route to study inter-planetary space.
Explorer 43, also called as IMP-I and IMP-6, was a NASA satellite launched as part of Explorer program. Explorer 43 was launched on 13 March 1971 from Cape Canaveral Air Force Station (CCAFS), with a Thor-Delta M6 launch vehicle. Explorer 43 was the sixth satellite of the Interplanetary Monitoring Platform.
Explorer 50, also known as IMP-J or IMP-8, was a NASA satellite launched to study the magnetosphere. It was the eighth and last in a series of the Interplanetary Monitoring Platform.
Plasma Wave Subsystem, abbreviated PWS, is an instrument that is on board the Voyager 1 and Voyager 2 unmanned probes of the Voyager program. The device is 16 channel step frequency receiver and a low-frequency waveform receiver that can measure electron density. The PWS uses the two long antenna in a V-shape on the spacecraft, which are also used by another instrument on the spacecraft. The instrument recorded data about the Solar System's gas giants, and about the outer reaches of the Heliosphere, and beyond. In the 2010s, the PWS was used to play the "sounds of interstellar space" as the spacecraft can sample the local interstellar medium after they departed the Sun's heliosphere. The heliosphere is a region essentially under the influence of the Sun's solar wind, rather than the local interstellar environment, and is another way of understanding the Solar System in comparison to the objects gravitationally bound around Earth's Sun.
Dynamics Explorer 1 was a NASA high-altitude mission, launched on 3 August 1981, and terminated on 28 February 1991. It consisted of two satellites, DE-1 and DE-2, whose purpose was to investigate the interactions between plasmas in the magnetosphere and those in the ionosphere. The two satellites were launched together into polar coplanar orbits, which allowed them to simultaneously observe the upper and lower parts of the atmosphere.
AMPTE-IRM, also called as AMPTE-Ion Release Module, was a Germany satellite designed and tasked to study the magnetosphere of Earth, being launched as part of the Explorer program. The AMPTE mission was designed to study the access of solar wind ions to the magnetosphere, the convective-diffusive transport and energization of magnetospheric particles, and the interactions of plasmas in space.
AMPTE-UKS, also called as AMPTE-United Kingdom Subsatellite, was a United Kingdom satellite designed and tasked to study the magnetosphere of Earth, being launched as part of the Explorer program. The AMPTE mission was designed to study the access of solar wind ions to the magnetosphere, the convective-diffusive transport and energization of magnetospheric particles, and the interactions of plasmas in space.
