Mars is one of the planets that is known from ancient times thanks to its very high brightness (-2,9 magnitude) on the night sky, that is surpassed only by Venus, Moon and sometimes Jupiter. Its present name, after the Roman god of war, comes from hematite dust that gives it a characteristic reddish or bloody color well visible with naked eye. It is interesting to note that the idea of planet’s divine patron related to fire or war is much older than Roman civilization. In ancient Babylon, a name of the Red Planet was Nergal from their god of war, fire and destruction. It was probably adopted by Mediterranean
Fig. 26) Schematic graph of dependences between various elements of the Martian realm (Jakosky and Phillips, 2001).
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civilizations like Egyptian (Hr-Dšr – Horus the Red), Hebrew (Ma'adim – the one who blushes) or Greek (Ares) and later on brought to Rome and again renamed to Mars. It is not clear how strong relations were between ancient civilizations but a similar pattern can be observed all around the world (Hindu: Mangala/Bhauma/Angaraka- “one who is red in color”, Chinese, Japanese, Korean and Vietnamese: 火星 – “fire star”). Numerous observations of Mars’ passages were recorded through centuries in Europe (among others by Aristotle, Galileo), far east (e.g. in Babylon), India and East Asia. There are also hints that South American civilizations possessed considerable observational knowledge about Mars but a great deal of it has been lost forever during conquistas.
A new era in observations has been opened by a development of first advanced optical devices, in the XIX century. In September 1877, during a perihelic opposition of Mars, the Italian astronomer Giovanni Schiaparelli constructed a first “detailed” maps of Martian surface (Fig. 27), within the limits of resolution. Several features introduced in Schiaparelli’s creation, survived till modern times (e.g. Tharsis, Elysium, Syrtis Major) giving a birth to present Martian nomenclature. Also in that time, a network of controversial canali, observed on Mars, ignited a vigorous discussion about the extraterrestrial life that goes on even now (see section 1.5). In course of time increasing
Fig. 27) Giovanni Schiaparelli's map of Mars (1877-1886), with famous channels. Reproduction from "Flammarion, La Planhte Mars" 1888. North of the map points downward (Source:
NASA).
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resolution of ground based telescopes allowed for revision and considerable reconstruction of older Martian maps.
The next great leap in our knowledge about Mars is dated on early 1960s with the first space exploration programs that were launched in the atmosphere of a space race between USA and Soviet Union (presently Russia). An early politics of these two countries was based on multiple missions of twin probes lunched one after another one in a narrow time window. Therefore the reader should not be surprised by indeed enormous list of Martian space missions, found in the literature, surpassed only by Earth and Moon related programs. Yet, among 46 spacecrafts/landers sent to Mars (including two Phobos probes) only 19 reached the planet and conducted the planed tasks. This great discordance is often termed as a Martian curse or Martian Bermuda triangle. The first attempts were made by Russians with a series of six probes: Marsinik 1, 2 (Mars 1960A, Mars 1960B), Mars 1, Sputnik 22, 24 (Mars 1962A, Mars 1960B) and Zond 1964A. None of them ever reached Mars (to be precise only Mars 1 succeeded in leaving Earth’s orbit). Also the first
Fig. 28) Images of the Mars’ surface from the early missions: A) The very first close-up of Mars - Mariner 4, B) Promethei Sinus - Mariner 9, C) The north polar cap - Mariner 9, D) Flow features-Nirgal Vallis-Mariner 9 (Courtesy NASA/JPL-Caltech and NSSDC).
A B
C
D
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American attempt, Mariner 3, shared the same fate. In spite of this failure, in 1965 its twin spacecraft, Mariner 4, successfully passed the Red Planet in a close flyby and transmitted the first close-ups of Martian surface (Fig. 28 A). These images, although of a limited quality, confirmed what was suspected already for a long time; Mars was a cold and dry planet with water locked at the poles (Fig. 28 B, C,). Subsequent successful flybys in 1969 (Mariner 6, 7) and later missions additionally grounded this image but also provided first evidences for past water or other liquid activity on Mars (Fig. 28 D). A next step, in the exploration, has been made by orbiters and first attempts to settle automated landers and rovers on the surface. The first probe successfully placed on the orbit around Mars belonged to USA (Mariner 9 in 1971). It arrived on Mars two weeks before a Russian probe, Mars 2 that carried also a lander module. An attempt to deploy the device ended with a crash that came into history as the first human made parts that touched the Martian surface. For the first truly successful landing one had to wait till famous Viking twin mission in 1976 that that provided first images of barren Martian desert covered with basaltic blocks (Fig. 29). Both landers were functional for extended period of time (Viking 1 till 1982) providing priceless data on Martian weather. In spite of this obvious success Mars was deserted for nearly 13 years. A great impact on this pause had the collapse of Soviet Union in early 1990s that brought the space race to an abrupt end. A next successful mission (MGS-Mars Global Surveyor) arrived to Mars as late as in 1996 and was followed, a year later, by Mars Pathfinder, the first successful rover mission. Presently there are three orbiter missions operating over the planet (Mars Odyssey, Mars Express and MRO-Mars Reconnaissance Orbiter) and two rovers on the surface (Spirit and Opportunity). It is also worthwhile to mention that the newest lander mission (Phoenix Lander) was launched in 4th of August of this year (2007) safely reach Mars, and already sends data.
Fig. 29) Rocky desert on Utopia Planitia landing site, northern plains – Viking 2 lander.
(Courtesy NASA/JPL-Caltech).
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