Cartography history. Introductory text.

The history of mapping the terrestrial planets and their moons borders with the history of the Earth cartographic study which is more than one thousand years old. The way of cartography from the remote ages till the ancient world is the way from the graphic outlined sketches which served to be kept in mind and to update cartography based on reproduction of metrical properties of space.
Critical point for developing cartography occurred in the epoch of geographical discoveries. In this period principles of plotting maps were clearly defined, schools appeared and conceptions on cartographic projections were developed as they had been studied fairly well. Of course, overstep into space, carrying out spaceborne surveys of the Earth and plotting maps for other celestial bodies have resulted in updating the existing principles of approach to cartographic works. The new contents of maps called for new methods of cartographic representation. However continuity was always preserved. Figs. 10-14 give the main idea of several important stages of the evolution of the terrestrial cartography.

Several stages which qualitatively differ in technical possibilities can be distinguished in the history of mapping the terrestrial planets and their moons: 1) observations with naked eye and sketches of the external appearance of the celestial bodies; 2) visual telescopic observations and map drawing; 3) telescopic photographing and plotting maps and atlases on the basis of the photo images; 4) research using space technology. Up-to-date (the 4th) stage of cartography based on spatial images is characterized in the section XII.
The beginning of the era of mapping Mercury dates back to 1889 when J. Schia-parelli made an attempt to show the location of the Mercury's relief features relative to the cartographic grid (Fig. 1). Several maps (M. Rudaux, G. McEwen and others) were plotted during the following years up to the forties of the XXth century. P. Ixwell named several features for the first time in 1896. All the presented elements of topography were only named in the map compiled by E. Anto-niadi (Fig. 2) and based on the observations of 1924-1934.
Several maps of Mercury were constructed during the sixties. They were compiled using both visual and phototelescopic observations (maps by D. Cruikshank, C. Chapman, A. Dollfus, G. Camichel and A. Dollfus, J. Murray, B. Smith). These maps differed significantly from the former ones. By that time the error in the estimate of the period of rotation had already been corrected for Mercury. It turned to be equal to 2/3 of the Mercury year. The authors of the maps took this fact into account (Fig. 3).

The history of mapping Venus dates back to the middle of the XVIIth century. It consists of several periods: the first period continued till the atmosphere was discovered; the second period is the period of studying the atmosphere till the beginning of space flights; the third period is the period of radar observations from the Earth, and, at last, radar mapping from the orbits of the Venus artificial satellites.

Fontana who was a lawyer and fond of astronomy, was the first to tell about spots on Venus in 1645. He discovered a dark region practically in the center of the planetary disk. G.D. Cassini noted the existence of black and bright spots when carrying out observations in Bologna, Italy in 1666-1667 (Fig. 4). In 1726 F. Bianchini plotted the first map of Venus on the basis of his observations. It represented "mares", "highlands" and other features (Fig. 5).

In 1761 M.V. Lomonosov observed Venus passing by the Solar disk, and concluded that the planet was surrounded by the atmosphere which was comparable with the Earth's atmosphere as for their densities. Lomonosov's discovery and the following observations carried out by W. Hcrschel in 1780 and by J. Schroeter in 1788, allowed to assert that the dark and bright spots being evident on the disk, displayed atmospheric phenomena, and they were not connected with any relief features. These phenomena are the most detailed in the photographic TV images of the cloudy coverage of Venus since they are located at the upper boundary of clouds and caused by atmospheric circulation. These images were obtained in the ultraviolet spectral band in 1974 by "Mariner 10" and during the "Pioneer-Venus 1" mission in 1978-80. Consequently drawings by G. Cassini and F. Bianchini are of historical interest only.

At the end of the fifties-the beginning of the sixties by both the USSR and the USA there were undertaken attempts to radar Venus from the Earth by both the USSR and the USA. The first successful experiments to map Venus basing on radar survey from the Earth date back to the period of 1969-1972. Measurements were conducted at different wavelength (3.8 cm; 12.5 cm; 12.6 cm; 70 cm) by several observatories. Several maps and sketch maps are given in Figs. 6-9. They were plotted using results of these observations from the Goldstone, Arecibo, Haystack-Westfort Observatories.

Radar maps, on the whole, well enough agreed with each other in a general way and confirmed that Venus possessed a certain variety of relief features. This conclusion was collaborated by the radar survey from the orbits of the "Pioneer-Venus" and "Venera 15,16" satellites to be used for mapping the planet.
It is practically impossible to date the beginning of the Moon observations with the naked eye and drawings of the topographic features which are apparent from the Earth. Drawing of the visible hemisphere of the Moon sketched by

W. Gilbert before 1603 (i.e. several years before a telescope was devised by G. Galilei) is usually given as an example of such drawings. This visual map of the Moon is presented in Fig. 15.

Drawings of the Moon based on instrumental observations appeared first in 1610. Galileo Galilei and Thomas Harriot were the first to open a new historical era of observations. G. Galilei inserted several engravings with the drawings of the Moon in his "Starry Messenger". Thomas Harriot was observing the Moon during the same period. He mapped the Moon independently giving denotations in letters and figures to the Lunar features (Figs. 16,17).

Further perfecting of the telescopic means resulted in significant progress in the Moon mapping in the second part of the XVIIth century. We can judge about this process by the maps of that period which have reached us. Their number is about several dozens. We see such well-known names of these authors as J. Hevelius, F. Grimaldi, G. Cassini (Figs. 18-20). These maps are distinguished by a larger number of details when presenting relief features, usage of different ways of relief drawing, regulation and design for the system of names in which an important role was played by G. Riccioli, and, at last, showing such a phenomenon as the Moon's libration.

The Lunar maps began to look more up-to-date half a century later, from the middle of the XVlIlth century. Systems of coordinates were developed. Projections were calculated. A grid of coordinates was given in each map. The map by Tobias Mayer was the first one of such a type (Fig. 21). It gives the main idea of the geographical coordinates of the Lunar disk. But these maps are still small scale maps of one sheet which represent the visible side of the Moon on the whole in the orthographic projection.

Maps composed of several sheets, appeared in the XlXth century only. Visible hemisphere was divided to sections. Maps of different sections became more and more detailed as for the surface relief features. Nomenclature of names was increasing simultaneously. W. Beer, J. Madler (Fig. 22), W. Lohrmann, J. Schmidt (Fig. 23) should be mentioned among the authors of these maps first of all. The German school asserts for a long period of time in the sphere of the Lunar cartography having replaced Italian and English schools.
In the first part of the XXth century the Moon maps were still compiled on the basis of visual telescopic observations though a lot of photographic images were being accumulated at the observatories simultaneously.
The first fundamental catalogues of control points were formed. Control of the relief features became more and more accurate. Maps by W. Goodacre, H. Wilkins, Ph. Fauth (Fig. 24) are thought to be the most significant ones for this period of time. Map of the Moon by Ph. Fauth is of the greatest interest among those based on visual telescopic observations. This is a map on a scale of 1:1,000,000 consisting of joined sheets. More than 17,000 features of the Lunar surface are given in it.

Photographic survey of the Moon was done on the edge of the XXth century for the first time. It resulted in a number of photographic atlases and separate maps prepared by different observatories of the world. The Atlas by M. Loevy and P. Puiseux was considered to be the best of them for more than half a century. It was compiled in the Paris observatory during the period of 1896-1909. F.F. Pctrushevsky who was a Russian explorer, proposed a detailed chart of the Moon's physical study which was, in essence, a chart of developing the basis for geological and other special maps of its surface and inner structural components.

The largest part of cartographic materials based on the results of the Moon photographic survey from the Earth, were developed during the period of 1960-1970. At this time the first data of space survey became available at this time. However atlases and maps compiled by the data obtained from the Earth were still actual. A set of maps by the Lunar and Planetary Laboratory of the Arizona University (USA), should be noted here first of all. It was plotted under the leadership of G. Kuiper (Figs. 25, 26). "Photographic Map of the Moon's Visible Hemisphere" was published in the USSR in 1967. It was plotted on the scale of 1:5,000,000 by the employees of the Sternberg State Astronomic Institute under the leadership of Yu.N. Lipsky (Fig. 27).

The first attempts to sketch Mars's surface using telescope date back to the second half of the XVII-th century. One of the first sketches of the planet was done in 1659 by Ch. Huygens (Fig. 28) who was a well-known Dutch astronomer and physician. An up7to-date sketch of Mars is given for comparison in Fig. 29. The following two centuries are marked by the appearance of a great number of sketches done by experienced observers (G.D. Cassini, W. Herschel, I. Schroeter, A. Secchi and others). The first maps of Mars resulted from these sketches but without a coordinate grid. The division of the planet in three regions was clearly seen in these maps. These regions are: highlands (vast, yellow-orange spaces), marc (dark, gray-blue spots), polar zones (bright white spots close to the Poles). The map by G. Schiaparelli was the result of this period of mapping Mars (Fig. 30). He proposed the system of names for the observed features which still exists today. It should be noted that Schiaparelli was the first to pay much attention to the so called canals (canale means water branches in Italian). Evidence of these canals had been marked by A. Secchi and by a number of other observers. Conception on their artificial origin found a lot of supporters among the observers. P. Lowell, the American astronomer, was the most fervent one. The map plotted by him (Fig. 31) significantly differed from the Mars maps of this period by a distinctive stylization of features and their reduction into a closed geo-metrical network. Discussion about the evidence of the canals lasted for about 70 years. Those who were against this conception, interpreted the stripes and lines observed as chains of spots, borders of regions, etc. Map by E. Antoniadi (Fig. 32) was an example of such an interpretation. It was considered the best map of Mars up to the fifties of our century. Finally the hypothesis of channels turned to be insolvent.

In 1973 the International Astronomical Union (IAU) chose the Mars map by G. de Mottoni as the basic map to represent names of the albedo features asserted by the special commission of IAU (Fig. 33). That was done to sum up the era of the observations from the Earth and to develop a system of the relief features observed from our planet.

So, a certain progress in mapping celestial bodies was achieved during more than three centuries of astronomical observations. This contribution was the most appreciable in the case of the Moon. It played an important role at the beginning of space research. But that was a way of delusions and errors in other cases (as with Mercury and Mars) though it is only of historic interest today. Nevertheless all these attempts promoted further extension and deepening of our knowledge on the bodies of the Solar system.