The small solids.
Asteroids or the small planetes.
The first discovery belongs to the Italian astronomer J. Piatzy who on the 1st of January 1801 discovered the small star,which was not registrated in star-catalogues. Later on several "star-looking" obects were found and called asteroids, i.e. "a starlike". Nowaday only the most large asteroids are discovered.
The reliable information about the asteroids can give only the spaceships from the small distance. On October 29, 1991 the american spaceship "Galileo" sent an asteroid's image to the Earth. It was the asteroid 951 Gaspra. Its demensions are 12*16 km. In August 28, 1993 "Galileo" got a new snapshot of Ida asteroid.
There will be a day, when the man appear, who showes where the comets rove, why they so differ from the planets and he will discover their neture.
Ceneca the Young.Procuring about the nature.63 y.
The comet is a celestial body of a great size, but a rare one... transparent. Sometimes there seen a core and the medium forms a kind of a tail, beard or dishevelled looks. It is a star with a tail, dishevelled.
V.I. Dal, the explanatory of the Russian language. 1863
|Comets (from the Greek kometes - langhaired) are the solid bodies in the Solar system. Moves along greatly stretched orbits. The central part of a head is a core. Diameter is 0,5 - 20 km, mass - 10^11 - 10^19 kg. The core is an ice body - conglomeration of frosted gas and dust. The comet’s tail consists of the gas and dust molecules (ions) coming from the Sun under the influence of the Sun’s beams. The tail length may be thousand million kilometers.|
Comets are the longest bodies in the Solar system. The comet in 1811 has a head that was 6 -8 times more than the Sun. The comet's tail in 1882 was more than the distance from the Sun to Jupiter. The tails of the comets are so rarefied that in the Earth are considered vacuum. Comets are "visible nothing". But in the centre of this "nothing" it is a solid core consisting of ice.
The comet state is variable: ones have the con tails, others the dust tails, and the third have both. There are another tails styles, there are also beards.
The Comet's motion.
Though the laws ruling the planets and comets motion their behavior and inhabited areas are greatly differ. The planet orbits are ellipses near to the circumferences. The comets orbits are stretched ellipses as it parabolas. The planets move in the thin disk plane in the same direction.The comet's motion was investigated by I. Newton and E. Gallei. They determined that the comets are moving in ellipses near to parabolas. The comets ways are very complicated and disodered. The comet may change its orbit at the crossroads of the giant planets (see the scheme).
Meteors and meteorites.
The fallinf from the sky fragments of stones and iron are called meteorites. They may be seen by everybody in the light night. Spending an hour looking in the sky you can see the falling star or meteor (from Greek meteora - the atmosphere occurrences). Sometimes there are the stars floods of meteors in the sky.
Meteorite from Mars
In the space surrounding our planet there are a lot of moving solid bodies of different sizes - from the pieces of dust to the great lumps with the diameter of tens and hundred meters. The more the bodies size the less they met. The pieces of dust approach the Earth every day and every hour. And the great lumps - once a hundred or thousand years. The following these muting effects are also different. The small body (mass of the parts of a gram) coming in to the terrestrial atmosphere with a high speed (tens of kilometers a second) is heated due to the air friction and Burnt in the 80 - 100 km height. The observer sees the greater fragment flies into the atmosphere (size like a fist, for example) with slower speed the atmosphere may serve like a brake and liquidate the space speed before the fragment has fully burnt. Then its piece will fall in the Earth’s surface. This is a meteorite. The meteorite falling shows the flying of a great ball in the sky and thunderstorm like sounds. And the mass of the flying body is very great the atmosphere can not liquidate all the speed and it cut into the Earth’s surface, leaving on in the space scar - the meteoric crater in hole. The most known one is a crater in Arizona meteorite crater (diameter 100km).
Meteorites are divided into three big classes: iron, stone and the iron-stone ones.
There occur the meteor floods, giving nearly the same number of meteors every year. (Perseids) and ones after the long periods of time (Geonids) this difference depends on the flood age. The two greatest meteors falling in the XX century occured in the territory of Russia: Tungysky and Sikhote-Alinsky.