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

1) The process of producing a map.
2) Math.: The operation of establishing → relations between two → sets in which one element of the second set is assigned to each element of the first set, as the expression y = x². Same as → function.

Verbal noun from → map + → -ing.

1) Naqšé bardâri;, → map.
2) Hamtâyeš, verbal noun of hamtâyidan literally "folding together, relating units together," from ham- "together," → com-, + tâ "fold, plait, ply; piece, part; single, a single unit of a pair," also a multiplicative suffix; Mid.Pers. tâg "piece, part," + infinitive suffix -idan.

A mature female horse or other equine animal.

M.E., variant of mere, O.E. m(i)ere feminine of mearh "horse," (cognates: O.Sax. meriha, O.Norse merr, Du. merrie, O.H.G. meriha, Ger. Mähre "mare"), probably of Gaulish origin (cf. Irish and Gaelic marc, Welsh march, Breton marh "horse").

Mâdiyân, from mâdé "female," → feminine.

Of or pertaining to the sea; produced by the sea.

From M.E. maryne, from M.Fr. marin, from O.Fr. marin "of the sea, maritime," from L. marinus "of the sea," from mare "sea, the sea, seawater," from PIE *mori- "body of water, lake."

Daryâyi "of, or pertaining to the sea," from daryâ, → sea.

1) A visible impression or trace on something, as a line, cut, dent, stain, or bruise (Dictionary.com).
2) To put a mark or marks on.

M.E., O.E. mearc, merc "boundary, sign, limit, mark" (cf. O.N. merki "boundary, sign," mörk "forest" (which often marked a frontier); O.Fr. merke, Goth. marka "boundary, frontier," Du. merk "mark, brand," Ger. Mark "boundary, boundary land"), from PIE *merg- "edge, boundary, border;" cf. Pers. marz, → frontier.

Dâj, variants dâq "brand, marking; hot," Hamedâni daj "in harvest, the sign placed on a wheat pile indicating not to be touched," dežan "acid, pungent;" Mid.Pers. dâq, dâk "hot," dažitan "to burn, scorch," dažišn "burning;" Av. dag-, daž- "to burn;" cf. Skt. dah- "to burn;" L. fovere "to warm, heat; " Arm. dažan "violent, wild;" Lith. degu "to burn;" O.E. fefor; E. fever. PIE base *dhegh- "to burn."

A blue star of visual magnitude 2.49, the brightest in the constellation → Pegasus. Markab is a relatively hot star of → spectral type B9, with a total luminosity about 200 times that of the Sun, a surface temperature of about 11,000 K, and a radius 4.3 times solar lying 140 light-years away.

Markab seems to be a corruption of Mankab in the original Ar. name of this star Mankib al-faras (منکب‌الفرس) "the horse's shoulder," from mankib "shoulder" + faras "horse," referring to Pegasus in Gk. mythology.

A galaxy with abnormally strong emission in the ultraviolet continuum and broad emission lines arising in a bright, semi-stellar nucleus.

Named after B. E. Markarian (1913-1985), an Armenian astronomer who made a catalog of such galaxies (1967-81); → galaxy.

A string of a dozen or so galaxies in the central region of the → Vigo cluster. The chain lies to the right of the cluster's dominant galaxy M87 and extends over nearly 2° on the sky. The chain's brightest galaxies are the lenticulars M84 and M86. At least seven galaxies in the chain appear to move coherently, although others appear to be superposed by chance.

→ Markarian; → chain.

Two → interacting galaxies, NGC 4438 and NGC 4435, located in → Markarian's chain of galaxies in the → Virgo cluster of galaxies. About 50 million → light-years away, the two galaxies are about 100,000 light-years apart. Gravitational → tidal forces from the → close encounter have ripped away at their stars, gas, and dust. The more massive NGC 4438 kept much of the material ripped out in the collision, while material from the smaller NGC 4435 was more easily lost.

→ Markarian galaxy; → eye.

1) An object used to indicate a position, place, or route.
2) A distinctive feature or characteristic indicative of a particular quality or condition.
3) Genetics: An allele used to identify a chromosome or to locate other genes on a genetic map (OxfordDictionaries.com).
4) → biomarker.

→ mark; → -er.

A → stochastic process, based on the classical → random walk concept, in which the probabilities of occurrence of various future states depend only on the previous state of the system and not on any of earlier states. Also called Markov process and Markovian principle.

Named after Andrey Andreyevich Markov (1856-1922), a Russian mathematician, who introduced this model in 1906; → chain.

A method for sampling from → probability distributions using → Markov chains. MCMC methods are widely used in data modeling for → Bayesian inference and numerical integration in physics, chemistry, biology, statistics, and computer science.

→ Markov chain; → Monte Carlo Method.

Fourth planet from Sun and the seventh largest. Mass 6.42 × 10²⁶ g (0.11 Earth's), radius 3397 km. Mean distance from Sun 1.52 → astronomical units. → Sidereal period 687 days, → synodic period 779.9 days. Surface temperature 248 K., → rotation period, or → sol, 24h37m22s.6. Mars' → obliquity is currently 25.19 degrees, but has changed dramatically over billions of years since solar system formation. Atmosphere more than 90% CO₂, traces of O₂, CO, H₂O. Two tiny satellites (→ Phobos and → Deimos), both of which are locked in → synchronous rotation with Mars.

Late M.E., from L. Mars the Roman god of war, Ares in Gk. mythology.

Bahrâm, from Mid.Pers. Vahrâm, from Vahrân "god of victory," from Av. vərəθraγna- "victory, breaking the defence, the god of victory." The first element vərəθra- "shield, defensive power," cf. Skt. vrtrá- "defence, name of a demon slain by Indra," Arm. vahagan name of a god (loanword from Iranian). The second element γna-, from Av., also O.Pers., jan-, gan- "to strike, hit, smite, kill" (jantar- "smiter"); cf. Mod.Pers. zadan, zan- "to strike, beat;" Mid.Pers. zatan, žatan; Skt. han- "to strike, beat" (hantar- "smiter, killer"); Gk. theinein "to strike," phonos "murder;" L. fendere "to strike, push;" Gmc. *gundjo "war, battle;" PIE *g^when- "to strike, kill."

The → zero point of elevation on Mars. It is the elevation at which the atmosphere pressure is 6.1 millibars, or 610 → Pascals. Atmosphere pressure has to be used because Mars has no ocean, and "sea level" cannot be used like on Earth. More formally, the datum is a fourth-order, fourth-degree surface of equal → gravitational potential (determined from the Viking orbiter spacecraft) such that the pressure of the atmosphere is 6.1 millibars (source: Lunar and Planetary Institute, USRA).

→ Mars; → datum.

A member of the family of → asteroids located at either of the stable → Lagrangian points (L4 or L5) of the orbit of → Mars.

→ Mars; → Trojan asteroid.

A special calendar for time reckoning on Mars in which the year consists of 668 → sols (687 Earth days) and each sol has 24h 39m 35s. For convenience, sols are divided into a 24-hour clock. Each landed Mars mission keeps track of local solar time at its landing site, which depends upon the lander's longitude of Mars. The Martian year begins when Mars arrives at the → vernal point of the orbit in its northward journey; in other words, when the solar longitude Ls is 0°. Mars' other seasons begin when Ls = 90° at → summer solstice, 180° at → autumn equinox, and 270° at → winter solstice. The year counts begin at Mars Year 1, at the northern → vernal equinox of April 11, 1955. The second half of that year was marked by a major dust storm (→ Mars' dust storm). February 7, 2021 marked the start of Year 36 on Mars. Year 37 will start on Dec. 26, 2022, and Year 38 on Nov. 12, 2024. On Earth, spring, summer, autumn, and winter are all similar in length, because Earth's orbit is nearly circular (→ eccentricity = 0.0167), so it moves at nearly constant speed around the Sun. By contrast, Mars' elliptical orbit (→ eccentricity = 0.0934) makes its distance from the Sun change with time, and also makes it speed up and slow down in its orbit. Mars is at → aphelion (249,200,000 km from Sun) at Ls = 70°, near the northern summer solstice, and at → perihelion (206,700,000 km) at Ls = 250°, near the southern summer solstice. The Mars dust storm season begins just after perihelion at around Ls = 260°.

→ Mars; → calendar.

A violent atmospheric disturbance on Mars marked by high amounts of dust, especially during spring and summer seasons of the planet southern hemisphere. The elongated orbit of Mars has several important consequences. During southern spring and summer, Mars travels near its → perihelion, while its southern pole is tilted toward the Sun. Therefore, its surface receives much more heat . The atmosphere's temperature near surface raises and since the upper layers of the atmosphere are cold, warm air moves up and takes dust particles upward. Each several years big storms occur and cover significant portions of the planet such that dust stays in the atmosphere for several weeks or months. See also → Mars' calendar.

→ Mars; → dust; → storm.

A quake on the → planet Mars, probably caused by some phenomena other than → tectonic plate motions. Unlike Earth, Mars seems to lack tectonic plates. Therefore, its quakes are thought to arise from the slow cooling of the planet over time, which causes the → crust to contract and develop fractures. These quakes can also come from the impact of → meteorites and possibly the movement of → magma deep below the surface. On April 6, 2019, the instrument called Seismic Experiment for Interior Structure (SEIS) on NASA's Mars → InSight Mission lander recorded quakes that appear to have come from inside the planet, the first time ever a likely marsquake.

→ Mars; → quake.

Of, relating to, or like the planet → Mars.

M.E. marcien, from L. Marti(us) of, belonging to → Mars + -an a suffix of adjectives.

A piece of rock that was ejected from the Martian surface into space by the impact of an asteroid or comet, and landed on Earth. So far about 100 Martian meteorites have been collected. These meteorites have elemental and isotopic compositions that match those of the Martian crust as measured by NASA's Mars exploration missions.

→ Martian; → meteorite.

A slender, cloudy projection sometimes seen to extend from the surface of → Mars to very high altitudes. Noted and confirmed by amateur astronomers on photos of Mars in March 2012, possibly similar plumes have been found on archived images as far back as 1997. The plumes reach 200 km up, which seems too high for them to be related to wind-blown surface dust. Since one plume lasted for more than 10 days, it seemed too long lasting to be related to → aurora. The origin of this phenomenon is not yet known.

→ Martian; → plume.