6.2 Find Russian equivalents to the following word combinations

a medium-sized star	космическое вещество
the mean diameter	бинарная (двойная) система
gradually	по крайней мере
artificial satellite	звезда средней величины
binary system	постепенно
at least	средний диаметр
interstellar matter	явление приливов и отливов
the Solar System tidal phenomena	искусственный спутник Солнечная система

6.3 Pay attention to the names of the planets. Mind their pronunciation

Mercury [´m∂:kjuri]	Mars [ma:z]	Uranus [´ju∂rns] ∂∂
Venus [´vi:ns] ∂	Jupiter [´du:pit∂]	Neptune [´neptju:n]
Earth [∂:θ]	Saturn [´sæt∂n]	Pluto [´plu:t∂u]

6.4 Read and translate the text The Universe and the Solar System

The cosmos or the universe as we view it today is made up of at least a billion aggregations of stars called galaxies. The galaxies vary in shape and texture and are divided into a number of general groups. Our own galaxy, the Milky Way, is classified as a spiral galaxy. The Milky Way in turn is a member of a supergalaxy that consists of seventeen galaxies of all types, concentrated within a radius of about one million light years.

Figure 2

Solar System:

The Solar System is a tiny family of the universe. There may well be millions of star systems like our own in the universe. It consists of the sun (a medium-sized star with a diameter of about 850,000 miles), its nine planets and a variety of smaller bodies ranging from satellites such as our moon to planetary dust. The sun’s mass is 33,000 times that of the earth and its temperature ranges from 6,000 degrees C at its surface to energy values equivalent to an estimated 25 million degrees C at its core. The sun is almost entirely gaseous, the most prevalent gas being hydrogen with traces of 65 other elements.

Of all nine planets Mercury is closest to the sun, followed by Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto in that order, the mean diameter of the solar system being about 7 billion miles. The inner planets are closer together and the outer ones are farther apart.

The planets rotate around their axes and revolve around the sun in elliptical paths determined by the force of the gravitation. Included in the solar system are the 31 satellites of the planets (not counting the earth’s artificial satellites), thousands of asteroids

which are minor planets ranging from one mile to 300 miles, comets, small masses of solid particles, held loosely together, and meteors.

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.