The claim that astronomers can not touch the objects they studied, is not always fair. At least in the solar system's something we can not only take pictures in detail, but also "touch" (at least by machines). It is not surprising, therefore, that its device is known to us pretty well.
Hardly anyone would dispute the fact that the earth revolves around the sun, and that with it revolves around the sun is a great variety of different bodies. We understand the forces which move under the influence of these bodies, and we can predict their movement. Actually, it is the study of the movement of celestial bodies has resulted in the finest section of astronomy – celestial mechanics.
Let us recall the history of the discovery of the first asteroid – Ceres. Italian astronomer J. Piazzi discovered it on the first night of the XIX century and then lost. However, knowing the trajectory along whichshouldCeres move (if true to our understanding of the solar system), has allowed German mathematician Gauss predict its position on future dates, and a year after the discovery of Ceres was found again, and exactly where it ought to be.
One can recall another textbook story of the discovery of Neptune "on the tip of the pen," but a much better understanding of the sky-proof mechanical device solar system is its practical use. Now a rare flight interplanetary spacecraft do without the so-called gravity assist – the flight path routed so tricky way that the different parts of its machinery accelerated attraction of large planets. Due to this it is possible to save a lot of fuel.
In short, we are very good (though not perfect) are investigated inmotionthe solar system. Worse is the understanding of their individual nature. The examples do not need to look far. Martian canals – which it was a great illusion! Observational astronomers drew maps of Martian amelioration network Astrobotany put forward bold hypotheses about the life cycle of Martian plants, inspired by science fiction drew pictures of their contact with the Martians (somehow worse than the other one) … The first images of the Red Planet, obtained by spacecraft, dispelled these fantasies even not in the dust – in smoke. You could go with something more channels were not those for which they were received. No, they just missed! Obsessive desire to see something on Mars, "such things" has played a cruel joke with the observers. On close examination the red planet was completely dead.
Now our understanding of Mars is completely different from what took place only some 50 years ago. Flies to Mars probe set, it visited landers, including the Mars rovers, drove across it a significant amount of miles. Constructed detailed maps of relief, temperature, mineral composition, magnetic field, the surface of Mars. Safe to say that at least on the surface and atmosphere of Mars, we know almost everything. Does this mean that the Martian studies, there is no room guesses? Oh, no!
The trouble is that the active phase of life of Mars has ended. Despite the proximity of the Red Planet, we still see only the result, but are unable to observe the process. To resort to analogies. After all, the Earth and Mars is not so different from each other. Why not assume that such forms of relief on both planets formed by similar processes? The first pictures of the Martian surface earthlings brought sad news not only the lack of channels. They found something interesting and – dry riverbeds. Suppose that on modern Mars, no water, but she was there in the past! For that, apart from the flowing water, can leave such marks? Add to that the layering of rocks of Mars, very similar to the structure of terrestrial sediments, and the presence of minerals that on Earth form only in a liquid medium … In short, all the data of Mars shows what was once probably a long time ago and very short-lived, it was water. But all these figures are, of course, circumstantial evidence. And here is the boundary beyond which the reader or listener astronomical news to keep your eyes open. For the result of observations at the conclusion of it runs a chain of logical reasoning and the additional assumptions that the text gets popular news is not always (this, however, is true of not only astronomy, but also other sciences).
Another good example – Europe, one of the Galilean satellites of Jupiter. Spectral analysis shows that the surface of the satellite is composed of water ice. But the average density of matter in Europe (3 g · cm-3) Is three times higher than the density of water, which means that most of the satellite is a rocky core surrounded by a less dense water jacket. The differentiation of the structure of Europe, there is a division on a more refractory and fusible core shell suggests that the bowels of the satellite have been, and possibly subjected to considerable heat. The source of the heat – probably tidal interaction with Jupiter and the other satellites of giant planets.
Fun of the situation is that the tidal heating is sufficient to support a part of the water shell of Europe in the liquid state. In other words, under the icy crust of Europe may be hiding an ocean … With this agreement and the structure of the moon's surface. She constantly "rejuvenated", talking about the almost complete lack of impact craters, and an extensive network of faults and fractures evidence for tectonic activity, which may be related to the mobility of solid ice to liquid substrate. Liquid water, a constant source of heat (the tidal deformation), the availability of carbon compounds (in the solar system, they are almost everywhere) – what do you need for life? And now ready bright headline: "The Jupiter are living beings!". Clearly, however, before flying to Europe research probe the presence of the ocean under the ice remains a hypothesis, and the possible existence of life in it centers – and at all fancy.
End of an era of anthropocentrism
To some it may seem strange, but compelling evidence that the solar system isnoin the center of the universe, were obtained only at the beginning of XX century. American astronomer Harlow Shapley got them, studying the spatial distribution of globular clusters (SHZS). At that time it was already known that globular clusters are spread unevenly across the sky, focusing primarily in only one half of the sky. But only managed to identify Shapley actual scale of the irregularity. Determine distances to globular clusters from observations of cepheids in them (see "Distance and age"), he found that the clusters are distributed in space is spherically symmetric, and the center of this distribution is not only not the same as the Sun, but is removed from it by tens thousand light-years! Shapley realized that the center of SHZS coincides with the true center of our galaxy, but for many years refused to acknowledge that in addition to her in the universe there may be other "Star Island." The giant size of the Galaxy so shocked Shapley that he simply could not imagine that in the universe there is room for something else.
Meanwhile, in 1924, the same year the American astronomer Edwin Hubble with the largest at the 2.5-m telescope of the Palomar Observatory for the first time, as astronomers say, "let the stars" Andromeda. In other words, he proved that her misty glow in fact generated by a myriad of individual stars, collected in a single system, similar to the Milky Way.
Thus it was proved that the sun is not in the center of the galaxy, and on its outskirts, and she galaxy is only one of many hundreds of billions of star systems.