An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

The central part of the → Earth's core, composed of solidified → iron and → nickel, and extending from a depth of about 5100 km to the center of the Earth, at 6360 km. Its radius is about 1/3 that of the whole core and is effectively decoupled from the → mantle due to the molten nature of the surrounding → outer core. The radius of the inner core is defined by a small increase in → compressional wave velocity at a radius of about 1200 km. Its density is about 12 g/cm³. The → temperature of the inner core has been estimated at 5000-7000 °C.

→ inner; → core.

A → near-Earth object whose → orbit lies always inside Earth's orbit.

→ inner; → Earth; → object.

One of the five → Lagrangian points, denoted L1, which lies between the two bodies on the line passing through their center of mass. In a → close binary star system mass transfer occurs through this point.

→ inner; → Lagrangian points.

A → Lindblad resonance expressed by: Ω_p = Ω - κ/m.

→ inner; → Lindblad resonance.

The planets Mercury, Venus, Earth and Mars collectively. T hey are also known as the terrestrial planets.

→ inner; → planet.

The smallest → circular orbit in which a particle can stably orbit a → black hole according to → general relativity without the risk of falling past the → event horizon. In other words, the ISCO is the inner edge of the → accretion disk around a black hole. Therefore, characteristics of accretion disks depend on ISCO. The radius of ISCO is calculated to be three times the → Schwarzschild radius (3 R_Sch). ISCO is closer to event horizon for rotating black hole.

→ inner; → stable; → circular; → orbit.

A dynamical model developed in France since 2003 which calculates the motion of → Solar System bodies with the highest accuracy. It integrates data obtained by NASA and ESA space missions. See, for example, A. Fienga et al. 2011, arXiv:1108.5546.

INPOP, short for Intégration Numérique Planétaire de l'Observatoire de Paris; → ephemerides.

1) The current, voltage, or driving force applied to an electric or electronic circuit or device.
2) Computers: Data which is transferred from outer external storage elements to the internal storage of a computer. → output.

From → in- + put, from M.E. put(t)en "to push, thrust, put;" O.E. *putian.

Darundâd, from darun "in" → in-, → intra-, + dâd "given," p.p. of dâdan "to give" (Mid.Pers. dâdan "to give," O.Pers./Av. dā- "to give, grant, yield," akin to L. data, → datum).

A catalog based on a pre-defined list of objects prepared for new observations, mainly using → space telescopes. → Ecliptic Plane Input Catalogue.

→ input; → catalog.

1) To mark with words, characters, etc., especially in a durable or conspicuous way.
2) Geometry: To draw within another figure so that the inner lies entirely within the boundary of the outer, touching it at as many points as possible: e.g. to inscribe a circle in a square.

From L. inscribere, from → in- + scribere "to write," from PIE *skreibh- (cf. Gk. skariphasthai "to scratch an outline, sketch;" Lett. skripat "scratch, write;" 0 O.N. hrifa "scratch"); PIE base *sker- "cut, incise."

Darveštan, darvisidan (on the model of neveštan, nevisidan "to write"), from dar-, → in-, + vešt-, vis- (see below) + -idan infinitive suffix. Vešt-, vis- from Mid.Pers. bišt-, bis- (nibištan, nibes- "to write"), from O.Pers. pais- "to adorn, cut, engrave," Av. paēs- "to paint, adorn," paēsa- "adornment," Mid.Pers. pēsīdan "to adorn;" cf. Skt. piśáti "adorns; cuts;" Gk. poikilos "multicolored;" L. pingit "embroiders, paints;" O.C.S. pisati "to write;" O.H.G. fēh "multicolored;" Lith. piēšti "to draw, adorn;" PIE base *peik- "colored, speckled."

An angle whose vertex lies on a circle and whose sides are chords of the circle.

Inscribed p.p. of → inscribe; → angle.

1) Something inscribed; the act of inscribing.
2) The entering of a name on or as if on a list.
3) A historical or religious text carved on stone, brick, or other hard surface.
4) A brief dedication, as of a book or a work of art.

Verbal noun of → inscribe.

Not secure; exposed or liable to risk, loss, or danger.

→ in-; → security.

The quality or state of being insecure; something insecure.

→ in-; → security.

Biology: To inject → semen into the reproductive tract a female animal or plant by artificial means.

From L. inseminatus, p.p. of inseminare "to sow, implant," from → in- + → semen "seed."

daršosaridan, from dar-, → in-, + šosar, → semen, + -idan suffix of infinitives.

The act or process of inseminating.

Verbal noun of → inseminate; → -tion.

A NASA lander designed to study the interior of the planet Mars. It will be a stationary mission, in contrast to NASA's famous Opportunity, Spirit and Curiosity rovers. Staying in place is necessary for its major science goals, which include learning more about the Martian composition, and how tectonically active the red planet is. InSight launched toward Mars on May 5, 2018, landed on Nov. 26, 2018, at the Martian Elysium Planitia, an equatorial zone just south of an ancient volcanic area. InSight will send back data about Mars' interior for about 1 Mars year, or 728 Earth-days. The lander uses sophisticated instruments, to delve deep beneath the surface and seek the fingerprints of the processes that formed the terrestrial planets. It does so by carrying out → seismology, heat flow measurements, and precision tracking.

InSight, short for Interior Exploration using Seismic Investigations, Geodesy and Heat Transport; → mission.

To be firm in a demand or course; refuse to yield (Dictionary.com).

L. insistere "stand upon, dwell upon," from → in- "upon" + sistere "take a stand," → resist.

Daristâdan "to insist" (Dehxodâ), from dar-, → in-, + istâdan "to stand," → resist.

The act or fact of insisting; the quality of being insistent.

Verbal noun of → insist.

Earnest or emphatic in dwelling upon, maintaining, or demanding something; persistent; pertinacious (Dictionary.com).

Adjective from → insist.