42,772 articles
Planetary objects proposed in religion, astrology, ufology and pseudoscience
Planetary objects proposed in religion, astrology, ufology and pseudoscience, also called planets in religion, ufology and mythology, are unconfirmed bodies like Vulcan, Planet X, and Nibiru.
Planetary parade
A planetary parade is a popular, non-technical name for several planets appearing in Earth's sky at once along a line or arc, a line-of-sight effect along the ecliptic.
Planetary radar
Planetary radar is the study of Solar System bodies, from the Moon to asteroids and comets, by transmitting radio signals and analyzing the returning echoes with large Earth-based dishes.
Planetary system
A planetary system, also known as an extrasolar system, is a set of gravitationally bound objects, including planets, that orbit a star; our solar system formed 4.6 billion years ago.
Planetesimal
A planetesimal is a kilometer-sized rocky or icy body that forms by dust coagulation in a protoplanetary disk and accretes into planets; asteroids and comets are surviving remnants.
PlanetQuest
PlanetQuest is a NASA Jet Propulsion Laboratory public engagement program on the search for planets around other stars, best known for founding the Night Sky Network in 2004.
Planets beyond Neptune
Planets beyond Neptune are hypothetical massive bodies, including the proposed Planet Nine, inferred from the clustered orbits of distant icy objects; only Pluto was ever found, in 1930.
Planets in astrology
In astrology, the planets are the Sun, the Moon, and the solar system bodies, treated as symbolic forces whose chart positions are read as influences on personality and events.
Planimeter
A planimeter is a mechanical instrument that measures the area of a plane shape by tracing its perimeter with a pointer; Jacob Amsler's polar design of 1854 became standard.
Plankton net
A plankton net is a cone- or cylinder-shaped device of fine mesh towed through water to filter and concentrate plankton, which collect in a bucket at the cod end.
Plant oils/soybean oil, epoxylated
Soybean oil, epoxylated (epoxidized soybean oil, ESBO, CAS 8013-07-8) is soybean oil with double bonds converted to epoxides; a PVC plasticizer-stabilizer, food-contact additive, and unapproved EU pesticide entry (EU ID 43).
Plant physiology and biochemistry : PPB
Plant Physiology and Biochemistry : PPB, Elsevier plant science journal, ISSN 0981-9428, founded 1987 from Physiologie vegetale, official FESPB journal since 2004, Q1, CiteScore 8.2.
Planta medica
Planta Medica is a peer-reviewed journal covering natural product and medicinal plant research, published in Stuttgart since 1953, first by Hippokrates Verlag and since 1987 by Georg Thieme Verlag.
Plantower PMS5003
The Plantower PMS5003 is a low-cost digital particulate matter sensor made by Plantower Technology in Nanchang, China, using laser light scattering to measure PM1.0, PM2.5, and PM10.
Plaskett's Star
Plaskett's Star is a massive O-type spectroscopic binary in Monoceros with two O stars orbiting every 14.4 days; John Stanley Plaskett found its enormous mass in 1922.
Plasma (physics)
Plasma, the fourth state of matter after solid, liquid, and gas, is an ionized gas of ions and free electrons making up 99% of visible matter, including stars.
Plasma acceleration
Plasma acceleration is an accelerator-physics method that uses plasma-wave electric fields, driven by a laser pulse or particle beam, to accelerate charged particles at gradients hundreds of times beyond conventional radio-frequency accelerators.
Plasma actuator
A plasma actuator is a flow-control device that uses an electrical discharge in air to impart momentum to a gas flow without moving parts, most often a dielectric barrier discharge.
Plasma beta
Plasma beta (β), in plasma physics, is the ratio of a plasma's thermal pressure to its magnetic pressure; values above 1 mean the plasma governs the field's behavior.
Plasma catalysis
Plasma catalysis is the coupling of non-thermal plasma with catalytic materials to drive chemical reactions such as CO2 conversion, nitrogen fixation, and methane reforming with electricity.
Plasma channel
A plasma channel is an elongated plasma column with lowest density on axis that guides intense laser pulses over many Rayleigh lengths, chiefly in laser wakefield accelerators.
Plasma chemistry
Plasma chemistry, a field within physical chemistry and plasma science, studies chemical reactions in ionized gases, enabling semiconductor etching, CO2 conversion, water purification, and plasma medicine.
Plasma control
Plasma control is the set of real-time feedback techniques used to confine, shape, and stabilize the plasma inside tokamaks, coordinating magnetic coils thousands of times per second.
Plasma crystal
A plasma crystal, also called a Coulomb crystal, is an ordered lattice of charged microparticles that forms in a dusty plasma, first observed in 1994.
Plasma diagnostics
Plasma diagnostics are experimental techniques used to measure plasma physical quantities, such as electron density, ion temperature, and magnetic fields, primarily using electromagnetic waves like microwaves.
Plasma diagnostics in space and low-temperature plasmas
Plasma diagnostics in space and low-temperature plasmas are measurement techniques, such as Langmuir probes and laser Thomson scattering, for electron density, temperature, and potential in the ionosphere, solar wind, and laboratory low-temperature plasmas.
Plasma dispersion function
The plasma dispersion function Z(ζ) is a complex special function introduced by Fried and Conte in 1961 for calculating wave propagation in a Maxwellian collisionless plasma.
Plasma display
A plasma display is a flat-panel display in which each pixel is a tiny cell of noble gas whose discharge excites phosphors, invented in 1964.
Plasma frequency
The plasma frequency is the natural frequency at which electrons in a plasma collectively oscillate against heavy ions; radio waves below it are reflected, which lets the ionosphere bounce shortwave signals.
Plasma imaging and tomography
Plasma imaging and tomography are plasma diagnostics in which cameras and detector arrays record radiation along many lines of sight, and tomographic inversion reconstructs the emitting material's distribution.