1. Hydrosphere
2. Cryosphere
3. The role of water in everyday life
4. Water pollution
VI. ATMOSPHERE
6.1 The Earths atmosphere
PRE-READING
Before reading the passage,answer all the following questions and discuss it with your partner. Then read the passage and find the facts supporting your ideas.
1. What do you know about the term atmosphere?
2. Is there life on Jupiter, Saturn or other planets of the solar system?
3. Is the Earth moving around the Sun or the sun moving around the Earth?
4. What parts does the atmosphere consist of?
5. Can life exist without oxigen?
TEXT
Task 1. Read, translate the text and be ready to do the exercises.
Atmosphere
An atmosphere (New Latin atmosphaera, 17th century, from Greek ἀτμός [atmos] "vapor" and σφαῖρα [sphaira] "sphere") is a layer of gases surrounding a planet or other material body of sufficient mass that is held in place by the gravity of the body. An atmosphere is more likely to be retained if the gravity is high and the atmosphere's temperature is low.
Ingredients for Life
Scientists have gathered enough information about other planets in our solar system to know that none can support life as we know it. Life is not possible without a stable atmosphere containing the right chemical ingredients for living organisms: hydrogen, oxygen, nitrogen, and carbon. These ingredients must be balanced: not too thick or too thin. Life also depends on the presence of water.
Jupiter, Saturn, Uranus, and Neptune all have atmospheres made mostly of hydrogen and helium. These planets are called gas giants, because they are mostly made of gas and do not have a solid outer crust.
Mercury and Mars have some of the right ingredients, but their atmospheres are far too thin to support life. The atmosphere of Venus is too thick: the planets surface temperature is more than 460 degrees Celsius (860 degrees Fahrenheit).
Jupiters moon Europa has a thin atmosphere rich with oxygen. It is likely covered by a huge ocean of liquid water. Some astrobiologists think that if life will develop elsewhere in the solar system, it will be near vents at the bottom of Europas ocean.
We live at the bottom of an invisible ocean called the atmosphere, a layer of gases surrounding our planet. Nitrogen and oxygen account for 99 percent of the gases in dry air, with argon, carbon dioxide, helium, neon, and other gases making up minute portions. Water, vapor and dust are also part of Earths atmosphere. Other planets and moons have very different atmospheres, and some have no atmospheres at all.
The atmosphere is so spread out that we barely notice it, yet its weight is equal to a layer of water more than 10 meters (34 feet) deep covering the entire planet. The bottom 30 kilometers (19 miles) of the atmosphere contains about 98 percent of its mass. The atmosphereairis much thinner at high altitudes. There is no atmosphere in space.
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Scientists say many of the gases in our atmosphere were ejected into the air by early volcanoes. At that time, there would have been little or no free oxygen surrounding the Earth. Free oxygen consists of oxygen molecules not attached to another element, like carbon (to form carbon dioxide) or hydrogen (to form water).
Free oxygen may have been added to the atmosphere by primitive organisms, probably bacteria, during photosynthesis. Photosynthesis is the process a plant or other autotroph uses to make food and oxygen from carbon dioxide and water. Later, more complex forms of plant life added more oxygen to the atmosphere. The oxygen in todays atmosphere probably took millions of years to accumulate.
The atmosphere acts as a gigantic filter, keeping out most ultraviolet radiation while letting in the suns warming rays. Ultraviolet radiation is harmful to living things, and is what causes sunburns. Solar heat, on the other hand, is necessary for all life on Earth.
Earths atmosphere has a layered structure. From the ground toward the sky, the layers are the troposphere,stratosphere, mesosphere, thermosphere, and exosphere. Another layer, called the ionosphere, extends from the mesosphere to the exosphere. Beyond the exosphere isouter space. The boundaries between atmospheric layers are not clearly defined, and change depending on latitudeand season.
The term stellar atmosphere describes the outer region of a star, and typically includes the portion starting from the opaque photosphere outwards. Stars with sufficiently low temperatures may form compound molecules in their outer atmosphere.
The Earth's atmosphere consists of a number of layers that differ in properties such as composition, temperature and pressure. The lowest layer is the troposphere, which includes the planetary boundary layer or peplosphere at its base. Three quarters of the atmospheric mass resides within the troposphere, and the depth of this layer varies between 17 km at the equator and 7 km at the poles. The stratosphere, from 20 to 50 km, includes the ozone layer, located at altitudes between 15 and 35 km, which absorbs ultraviolet energy from the Sun. The mesosphere, from 50 to 85 km is the layer in which most meteors burn up. The thermosphere extends from 85 km to the base of the exosphere at 690 km and contains the ionosphere, a region where the atmosphere is ionised by incoming solar radiation. TheKármán line, located within the thermosphere at an altitude of 100 km, is commonly used to define the boundary between the Earth's atmosphere and outer space. The exosphere extends from about 690 to 1,000 km above the surface, where it interacts with the planet's magnetosphere. Each of the layers has a different lapse rate, defining the rate of change in temperature with height.
(Retrieved from: https://en.wikipedia.org/wiki/Atmosphere)
Glossary
Hydrogen -
Oxygen -
Nitrogen -
Carbon -
Helium
Argon
Neon
Minute portions
Word study
