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There exist several hypotheses of the origin of the Solar System, there are two of
them:
The “catastrophic” theory. This held that the planets were formed of material torn
away from the sun by the action of another star, either by collision or by tidal
phenomena. This star may have been one which its proper
motion brought into the
neighbourhood of the sun or it might have been a “companion”, assuming the sun to
have once been a double star, like many binary systems in the universe.
The nebular theory. This theory suggested that the sun was originally surrounded
by a mass of gas extending beyond the limits of the present solar system. This nebula
resulted either from the evolution of the sun, or from the capture by the sun of a cloud
of interstellar matter, which, condensing, separated from it and gradually
agglomerated to form the planets. Our solar system seems
to have developed
according to this latter pattern.
6.5 Say whether the following statements are true or false
1. Galaxy is a great star system.
2. Our own galaxy, the Milky Way, is classified as an elliptical galaxy.
3. Seventeen galaxies of a supergalaxy are concentrated within a radius of about one
million kilometeres.
4. The Solar System consists of the sun, its nine planets and a variety of smaller
bodies.
5. The sun’s temperature is equal at its surface and at its core.
6. The sun is almost entirely solid.
7. Of all nine planets Pluto is closest to the sun.
8. Asteroids are small masses of solid particles, held loosely together.
9. There exist several hypotheses of the origin of the Solar System.
6.6 Fill in the blanks with the suitable words from the text
1. Of all nine planets Mercury is ………. to the sun .……... by Venus, Earth, Mars,
..…….., Saturn, Uranus, Neptune and Pluto in that order.
2. The ………. planets are closer together and the ………. ones are farther apart.
3. The planets ………. around their axes and ………. around
the sun in elliptical
………. determined by the force of ………. .
4. The ………. diameter of ………. is about 7 billion miles.
5. As to the ………. of the Solar System there exist several hypotheses.
6. The ………. theory suggested that the planets are formed of material torn away
from ………. by the action of another star.
6.7 Ask questions to which these sentences are the answers
1. The Universe as we view it today is made up of at least a billion aggregations of
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stars called galaxies.
2. Yes, there may be millions of star systems like our own in the universe.
3. The approximate age of our Solar System as determined by the radioactive
method is about 4,5-5 thousand million years.
4. The planets rotate around their axis and revolve around the sun.
5. No, Neptune isn
’
t the farthest planet to the sun. It’s Pluto.
6. According to the “catastrophic” theory the planets were formed of material torn
away from the sun by the action of another star.
7. Our Solar System is believed to have originated from an immense cloud of gas
and dust.
8. Stars differ in surface temperature that’s why they are of different colour: white,
blue, yellow and even red.
6.8 Translate into English
1. Галактики различаются по форме и структуре. Млечный Путь – это
спиральная галактика.
2. Солнечная система – это крошечная частица вселенной.
Она состоит из
солнца, планет, спутников, космической пыли.
3. Структура солнца газообразная. Преобладающий газ – водород.
4. Солнечная система включает 31 спутник планет (не считая искусственных
спутников Земли).
5. Астероиды – это малые планеты, размером от 1 мили до 300 миль.
6. Небулярная теория предполагает образование небесных тел путем
концентрации космического вещества.
6.9 Read and translate the dialogue. Reproduce it
A.: Did the sun and the planets form at the same time?
B.: You see, there exist several concepts of the origin of the solar system. Some of
them suggest that the sun and the planets originated at the same time from a
tremendous cloud of gas, mostly hydrogen and cosmic dust.
A.: And what do other hypotheses suggest?
B.: Other hypotheses suggest that the planets are younger than the sun, that first the
center of the cloud condensed and became a star – the sun, and then various densities
gave birth to the planets.
A.: I see.
B.: But it must be said that there is still no generally accepted
theory to explain how
and when the sun and the planets formed.
6.10 Using the given chart , answer the following questions
1. Which planets have a longer day than year?
2. Which planet has the most moons?