People were engaged in agriculture in the stone age, 30 – 35 thousand years ago. This is evidenced by the notches on animal bones and rocks, cave paintings. This is, perhaps, the earliest “scientific notes”, in which the authors noted the different phases of the moon and count days and nights.
Monitored by our astronomical instruments, the universe consists by weight of about 76 percent hydrogen and 23 helium. Only slightly more than one percent accounts for all other elements of the periodic table.
It is estimated that the galaxy contains more than a hundred and twenty billion stars and to represent its enormous size, we will give one comparison: if the path from the Sun to Earth light travels in 8 minutes, the diameter of the galaxy it will for a hundred thousand years.
To show the progress made over half a century in the study of the Universe, astronomer Paul Couderc came to a startling comparison. Suppose that all known astronomy to 1900 area of the Universe displayed on the plan area of one square meter. Continue reading
Periodic comet attracted by the Sun, sent to him, but pass due to the same sensitivity to the solar wind, which causes the surrounding cloud of dust and gases blown away from the Sun. People believe that the tiny particles of solar wind will impact more than large particles, but this assumption is wrong. If this were so, then how to explain the continued existence of the Asteroid Belt, which includes debris of any size is not affected, apparently, by the solar wind. The small object may lose velocity faster than the larger object because of differences in gravity, but if they are sensitive to solar wind, it occurs the same effect, – they are repelled equally. The comet, which (eventually) reach the Sun, with a very repeatable trajectory around the Sun, losing a lot of water vapor so that the ratio of substances in their composition is aligned at the expense of pushing away by the solar wind. In short, they lose their cover. They fly up with acceleration from the external space, but at this time do not change direction, going outside, and face (with the Sun). In fact, comets complete their orbits, coming nearer in the process, getting closer and closer to the Sun. Continue reading
Universe – all existing world, and not having borders in time and space. The earth is one of nine planets that revolve around the sun in very similar orbits on circles. Earth is the third planet from the Sun after mercury and Venus, after Earth comes Mars, ending the inner group of planets . different small size and solid surface. Followed by the giant planets of the outer group . consisting of hydrogen and helium-Jupiter, Saturn, Uranus, Neptune and little Pluto. In the interplanetary space sweep the comets and meteoric bodies. Seven of the nine planets have satellites . they just opened more than 50. The Earth satellite – the Moon is large (fifth largest and first with respect to the mass of the planet) and causing tidal movement, covering the whole Earth from the core to the surface.
The sun and its planets are called Solar system . The diameter of the Solar system 12 billion km from the Sun significantly more Land – in 333 thousand times the mass, and 109 times the diameter. The average distance from the earth to the Sun is 149.6 million km is taken as the astronomical unit to measure distances in the Solar system. Continue reading