The sun, the planets revolving around it and around speeding satellites, asteroids, kometoidai, meteroidai, tarplanetin material objket the gravitational and magnetic fields, radiation is elektromagetiniai solar system. The dimensions of the planetary system, measured in the most distant planet Pluto's orbit mean diameter equal to about 12 billion kilometers (80 astronomical units).
Planetary system for 35-200 av-shrouded Edvorto kometoid Kuiper belt, and for 50-200 thousand. AV - Ortho kometoid spherical cloud. The outer edge of the cloud coincides with the range in which the solar gravitational force to coincide with the nearest stars in the force of gravity.
Planetary orbits around the Sun such related circumferences elliptical orbits whose plane inclined at a small angle to the ecliptic plane, the greatest inclination to the ecliptic (17 degrees) to the orbit of Pluto. About an axis of rotation of the Sun and the planets around the sun Soaring in the same direction. Artimaiusiu stars Solar System Flying against 19.7 km / s constellation of Hercules. Around the galactic center of the solar system orbits nearly circular orbit of 220 km / s velocity of the galactic center and rotates through 230 million years ago.
The seventeenth century. finally had to abandon the claim that the Earth is the center of the world and to recognize that this is just another planetary system. And Newton has shown that in the sky as the Earth, by the same laws of mechanics, physicists have a problem scientifically explain the origin of the solar system. The eighteenth century. in the second half of the philosopher I. Kant and mathematician, physicist, and PS Laplace developed the hypothesis that the Sun and its planets formed from the original rotating cloud of gas. The influence of the pull of gravity, clouds retreated, and turning it on susiplojo. Cloud formed in the center of the central ball, which evolved from the sun, and the remaining surrounding disk, and rotating traukdamasis, eroded into the gas and dust rings, which eventually became the planets. Kant and Laplace's ideas have remained until this day. Subsequent studies of astronomy and physics has enabled more precise definition of this hypothesis, although it has so far not turned into a rigorous, unambiguous theory, there are even different versions of it. Solar system formed two types of planets: the Sun closer - quite dense, small-size (Mercury, Venus, Earth, Mars), and further from the Sun - low density of large planets (Jupiter, Saturn, Uranus and Neptune), Pluto is an exception, reminiscent of the great Earth satellite. Recently reported that the major planets have dense core several times larger than Earth-like planet. The nucleus is surrounded by a large and rare hydrogen and helium envelope, which apparently attracted a massive planet formed from primordial gas and ambient dust.
Twentieth century. the second decade of the astronomer George. Denim (jeans), proposed the formation of other planetary hypothesis - that they came together as the sun goes down with another star and after removal of part of the material. Then it is shown that the Sun and planets are about the same age and similar chemical composition, the hypothesis had to be abandoned. Because the Sun is an ordinary star, the planet's collision occurred at random, but natural evolution path, it is very likely that many other single stars have planets. Unfortunately, even the nearest stars are distant from us in four or more light years away, so there is even the highest resolution telescopes near impossible to read the small dark objects (cosmic Hubble telescope has only observed brown dwarf, red giant borne around. Planet periodically disrupts the star radiation make those changes and attempts to detect. A few decades ago it was announced that found the planet to one of the closest star - the star Barnard, however, revealed that these observations were inaccurate. discovery, as is often the case, was not where it was expected. in 1994 on. was discovered three Earth-sized planets orbiting pulsar - a neutron star. It is impossible to believe that they were formed before the collapse and the surviving stars of the explosion, but their formation after the explosion is also difficult to explain, which is still a mystery of astrophysics. was soon enough to reliably evidence that the planet exists and the number of normal stars, which appeared in Besancon large as Jupiter, the planet, traveling at close to their stars (the Sun is completely alien to the system). Thus, the planetary system, apparently, can be very different, and the formation of the theory will still revise and complete. A new field of astronomy - the stars planet science, which in the near future promises exciting new discoveries.
Earth rotates on its axis from west to east. These points of the equator is moving 465 m / s, so the Earth rotates on its axis every 24 hours. This leads to the rotation of day and night change. The sun side of Earth atsisukusioje day, but on the opposite side - the night. The exception is the North Pole and areas close to them. There is a certain period of the day and only a certain period of time - only at night. Seasons (spring, summer, autumn, winter) change is due to: a constant 23.5 angle between the Earth's rotation axis and the perpendicular plane of its orbit, Earth's revolution around the Sun, Earth's axis fixed in space (it is always parallel to itself). Earth's rotation axis is inclined to the north of the Sun, so the angle between the axis and the direction of the Sun is less than 90 .
Solar System rotation axis tilt angles. Uranus orbits the Sun in a lying position, Mercury due to the low inclination of the axis does not have the time, who are on Earth, Mars, Saturn and Neptune.
The observer, located in the northern hemisphere, it seems that the Sun moves higher in the sky and the day is an arc of more than 12 hours. Meanwhile, the Earth reaches the point C, the angle between the axis of rotation and the direction of the sun gets higher than 90 , the sun moves lower arc, the day is less than 12 hours. Positions B and D, the angle between the Earth's rotation axis and the direction of the Sun at 90 . And everywhere on Earth Day and night lasts 12 hours. Due to the fact that the Earth actually orbits in elliptic irregular (non-circular) orbit around the Sun, which is one of the ellipse foci, takes different seasons. Northern Hemisphere spring time equal to 93 days of summer - 94 - in the autumn 90, winter - 89 days. Northern Hemisphere spring and summer of astronomical conjunction lasts longer than eight days, autumn and winter. Astronomical seasons beginning in the northern hemisphere is as follows:
- Spring - 03 20-21 (day of equal night);
- Summer - 06 21-22 (the longest day, shortest night);
- Autumn - 09 22-23 (day equals night);
- Winter - 12 22-23 (the shortest day, longest night).
It is interesting that the coldest time of year the northern hemisphere, on January 3., The Sun is closest to Earth (147 million. Miles), and the warmest years, on 3 July., - Farthest (152 million. Km). Distance from the Sun Earth receives about 3% less solar energy, because the Northern Hemisphere summer a little cooler and winters milder than in the Southern Hemisphere. There, the Earth is closest to the sun in summer, and the farthest - in the winter. Of course, the climate in the Southern Hemisphere oceans affect the abundance of the northern hemisphere - a huge Eurasian continent., Br> visual movement of the Sun from the sky we see the sun, traveling around the Earth. Seen from Earth, it seems that Sun is going through one year of the circle. This annual outdoor Way of the Sun called the Ecliptic (gr. ekleiptike - Eclipse). Sun passes through 13 constellations, 12 of which are called zodiac constellations (gr. zodiac comes from the zoon - animal; exclude Zodiac Ophiuchus, which is between Scorpio and the Sun):
- winter - a Sagittarius, Capricorn and Aquarius constellations;
- spring - a fish, Aries and Taurus;
- summer - a Gemini, Cancer and Leo constellations;
- Autumn - a constellation of Libra, Scorpius and Ophiuchus constellations.
At noon, it is not possible to see which constellation the Sun because of its strong light overshadows the relatively weak stellar glare. So how to determine the position of the Sun in the sky constellations respect? Knowing which constellation the Sun is at midnight, you can specify where it is noon. As a result, at midnight to be the highest above the horizon and the constellation of the zodiac according to foresee where the midday sun. For example, if the highest above the horizon at midnight is the constellation Virgo, the midday sun is the constellation of Pisces.
Looking into the starry night sky, it seems that the stars move. However, the locking of any stationary object in the evening and the morning, we find that stars the situation is quite different.
Visual movement of the stars in the sky can be seen in quickly. It is enough to watch the star so that the viewing direction coincides with some fixed object, such as the tops of the trees, the roof ridge. How long to stand in one place, we see that pretty soon the stars will change.
Mercury, Venus, Earth and Mars, the comparative sizes. Mercury suit the more satellites in the Earth or Venus.
After a long sky picture shows that it rotates about an axis which is directed almost to the northern star.
Thus, visual stellar rotation visible on the Earth's rotation on its axis directed to the northern star.
Visual planetary motion of stars in the background sky is much more complex than the Sun or Moon. Planetary moves it to one, it's the other way, thus emphasizing the celestial sphere, or zigzag stitches. This movement is repeated periodically, such as Mercury - every 116 days, Mars - every 780 days.
The orbit of prolixity distance between the Earth and the Sun during the quarter, the daily changes of 7000 km.
Prior to 1500 million. the Earth during the year turned on its axis 900 times (the current day lasted 10 hours) prior to 500 million. year - 380 times, and now turns around only 365 times. Earth day every 50,000 years longer by one second.
Greek astronomer Hipparchus (Hipparchia, about 190-120 m. Ave. BC). Solar apkeliaujam year zodiac circle divided into 12 equal size (length of 30 and 16 wide) areas of the sky. He told the Sun and the presence of the corresponding zodiac constellation of the time:
- 03 21 - 04 20 Aries
- 06 22-07 22 Cancer
- 04 21 - 05 21 Ox
- 07 23 - 08 23 Leo
- 05 22 - 06 21 Gemini
- 08 24 - 09 23 Virgo
- 09 24 - 10 23 Libra
- 12 22 - 01 20 Capricorn
- 10 24-11 23 Scorpio
- 01 21 - 02 19 Aquarius
- 11 24 - 12 21 Sagittarius
- 02 20 - 03 20 Pisces
Through more than 2,000 years is no longer a relevant Sun Star constellation of Hipparchus at a specified time, but is shifted over one character, for example, if the Sun was in Aries time of Hipparchus constellation, it is now, at the same time, it is only the constellation of Pisces - So the other newspapers we read horoscopes, as in all times there people who discover the connection between the Sun, Moon and planets and constellations in the background of the peoples and the development of personalities.
Great companion comparative sizes. Pluto and Mercury for the satellite and the planet at the class.