terrestrial planets lab

NAME- Gurleen Kaur. The Inner Planets This section describes the main characteristics of the four planets closest to the sun. Introduction 1. Which planets are often called the terrestrial planets? – The planets that are often called the terrestrial planets are Mercury, Mars, Venus, and Earth. 2. What are three similarities among the inner planets? – They are small, dense, and have rocky surfaces. Use the planetary data table to answer questions 3 and 4. 3. Rank the inner planets according to diameter. Rank the planet with the greatest diameter as 1. 4 - Mercury 2 - Venus. 1 - Earth 3 - Mars 4. Which planet rotates on its axis in about the same amount of time that Earth does? - Mars

5. The drawing below shows the sun and the four inner planets. Label the inner planets according to their place in the solar system. The Inner Planets (continued) Mercury 7. Circle the letter of each sentence that is true about Mercury. a. Mercury’s surface has many craters. b. Mercury has no moons. c. The interior of Mercury is composed mostly of the element mercury. d. Mercury is the planet closest to the sun. 8. Why does Mercury have a greater range of temperatures than any other planet? – Mercury has a greater range of temperatures than any other planet because it is so close to the sun than the side facing the sun gets very hot during the day. However, most of. The heat escapes into space at night because Mercury has almost no atmosphere. The temperature then becomes very cold. T h e S o l a r S y s t e m Mars Earth Venus Mercury - The Earth’s dense inner core is made of mostly iron and nickel. 6. What is Earth’s dense inner core made of?

16. The atmosphere on Mars is composed mostly of – carbon dioxide. 17. Is the following sentence true or false? There are no canals on Mars. - True 18. Why do some regions on Mars look darker than others? – Some regions on Mars look darker than other because wind storms arise and blow the dust around on the surface of Mars. The darker regions are often where the dust has been blown away. 19. Circle the letter of each sentence that is true about Mars. a. The rocks on Mars are covered with a rusty dust. b. Mars has seasons because it is tilted on its axis. c. Mars has many large oceans on its surface. d. Mars has giant volcanoes on its surface. 20. What are the two moons of Mars? a. Phobos b. Deimos 21. Complete the table to compare and contrast characteristics of Earth and Mars. Characteristics of Earth and Mars Characteristic Earth Mars Atmosphere Mostly nitrogen and oxygen a. Mostly carbon dioxide Moons One b. Two Seasons c. Yes Yes Surface Solid and rocky d. Solid and rocky Water e. 70% water, or mostly water At poles and possibly underground f. Use the table to identify which characteristics of Mars make it difficult or impossible for humans to live there without life support. – Humans could not survive without life support in an atmosphere of mostly carbon dioxide. The scarcity of water might also cause problems. T h e S o l a r S y s t e m

The Solar System ■ Section Summary The Inner Planets Guide for Reading ■ What characteristics do the inner planets have in common? ■ What are the main characteristics that distinguish each of the inner planets? Mercury, Venus, Earth, and Mars are more similar to one other than they are to the five outer planets. The four inner planets are small and dense and have rocky surfaces. These planets are often called the terrestrial planets, from the Latin word terra , or “earth.” Earth is unique in our solar system in having liquid water at its surface. Earth has a suitable atmosphere and temperature range for water to exist as liquid, gas, or solid. Earth has an atmosphere that is rich in oxygen. Nearly all of the remaining atmosphere consists of nitrogen, along with small amounts of other gases such as argon and carbon dioxide. The atmosphere also includes water vapor. Mercury is the smallest terrestrial planet and the planet closest to the sun. Mercury is smaller than Earth’s moon and has no moons of its own. The planet’s interior is probably made of iron, and its surface has many plains and craters. Because the planet is so close to the sun, the side facing the sun reaches temperatures of 430  C. However, the temperature drops to –170  C at night. Venus is similar in size and mass to Earth. Venus’ density and internal structure are similar to Earth’s. But in other ways, Venus and Earth are very different. Venus rotates from east to west, the opposite direction from most other planets and moons. The pressure of Venus’s atmosphere is 90 times greater than the pressure of Earth’s atmosphere. The atmosphere is mostly carbon dioxide, with clouds partly made up of sulfuric acid. The carbon dioxide in the planet’s atmosphere traps the sun’s heat, causing the surface temperature of Venus to be about 460  C. This trapping of heat by the atmosphere is called the greenhouse effect. Venus is covered with rock, similar to many rocky areas on Earth. Venus also has many volcanoes and broad plains formed by lava flows. Mars is called the “red planet.” Its surface is covered with red dust. The planet Mars has a very thin atmosphere that is mostly carbon dioxide. Temperatures on the surface range from –140ºC to 20ºC. Images of Mars show a variety of features that look as if they were made by ancient streams, lakes, or floods. Scientists think that a large amount of liquid water flowed on Mars’s surface in the distant past. At present, liquid water cannot exist for long on Mars’s surface. However, some water is frozen in the planet’s two polar ice caps. A large amount of water may be frozen underground. Like Earth, Mars is tilted on its axis, so its seasons T h e S o l a r S y s t e m

15. terrestrial planets – The first four planets from the sun: Mercury, Venus, Earth, and Mars. They are the Earth-like planets with rocky surfaces. 16. greenhouse effect – The trapping of heat by the atmosphere. The Solar System ■ Enrich Atmospheres of Earth and Venus Earth and Venus are about the same size. Still, it is hard to imagine how the conditions on the surfaces of Earth and Venus could be more different. Earth’s surface is cool, while that of Venus is 460  C. You have learned that this is because Venus is closer to the sun than Earth and because of the greenhouse effect caused by the carbon dioxide gas in Venus’s atmosphere. Earth has a smaller greenhouse effect because there is much less carbon dioxide in its atmosphere. Why is this so, if the two planets are so similar in other ways? Both Earth and Venus get much of their carbon dioxide from the same source: erupting volcanoes. Unlike on Venus, Earth’s carbon dioxide is constantly removed from the atmosphere by two things that Venus lacks: liquid water and green plants. Carbon dioxide dissolves easily in water. Once it is there, it joins with other chemicals to form solid substances that become part of sea- floor rocks. This carbon dioxide is trapped unless the rock melts. As a result, much of Earth’s carbon dioxide is “locked up” in these rocks. Plants also absorb carbon dioxide and lock up some of the gas. On Venus, carbon dioxide simply builds up in the atmosphere. Use the diagrams to answer the questions below on a separate sheet of paper. 1. Figure 1 shows, in very simple terms, the pathways taken by carbon dioxide on Earth. According to the diagram, where does carbon dioxide go when it leaves Earth’s atmosphere? – Carbon dioxide is either dissolved in the oceans or absorbed by green plants.

2. On Earth, where is most of the carbon dioxide located at any one time? – is locked up in rocks. On Venus, where is most of the carbon dioxide located at any one time? – It is in the atmosphere. 3. On Earth, how does carbon dioxide move from the atmosphere into rocks? Why does this movement not occur on Venus? – On Earth, carbon dioxide dissolves in ocean water. While there, it reacts with other chemicals to form rocks. On Venus, there are no oceans in which the carbon dioxide can dissolve. 4. If the temperature of Earth’s surface were to increase by 100  C, what would happen to the amount of carbon dioxide in the atmosphere? Why? – If Earth’s temperature increased by 100  C, the amount of carbon dioxide in the atmosphere would increase because the oceans would evaporate, and green plants could not live. Without these, the carbon dioxide would have no way out of the atmosphere. 5. If all carbon dioxide coming out of volcanoes were to remain in the atmosphere, what further effect would this have on Earth’s temperature? – The carbon dioxide would increase the greenhouse effect and would further warm Earth’s surface. T h e S o l a r S y s t e m