Tomás Monzón May 13, 2008Earth Space Science Period 6

Chapter 28 Assessmentp. 772 - 773

1. On what does the light-collecting power of a telescope depend?b. The area of the opening through which light

2. What is the same for all types of electromagnetic radiation?d. Speed

3. What type of radiation does not have to be observed above Earth’s atmosphere?

a. visible light

4. During which of the following is the Sun directly overhead at 23.5 north latitude?

a. summer solstice

5. Which of the following provides evidence that the Earth is rotating?b. The plane of a Foucault pendulum, appears to shift its orientation.

6. Which of the following is in correct order?b. waxing gibbous, full moon, waning gibbous, third quarter

7. List the various forms of electromagnetic radiation according to wavelength, from shortest to longest.

In order of shortest to longest wavelength, the forms of electromagnetic radiation are: gamma rays, X rays, ultraviolet radiation, infrared radiation, microwaves, and radio waves.

8. Why must some telescopes be launched into space? Recall that the ultimate goal of telescopes, and of astronomers, is to be

able to observe and analyze all forms of electromagnetic radiation, not solely visible light, which is what the human eye perceives. The Earth’s atmosphere blocks either entirely, or at least in part, other forms of electromagnetic radiation, such as infrared and ultraviolet radiation, gamma rays, etc. When the atmosphere allows such wavelengths past, the images produced are blurred. Thus, telescopes must be launched into space to perceive these radiations.

9. List the types of shadows as well as the types of eclipses that will be seen by an observer on the unlit side of Earth.

The first diagram (top) illustrates a total lunar eclipse. Where the Moon enters the Earth’s umbra in its entirety. An observer on Earth will witness a reddish colored moon, which occurs as a result of the

Tomás Monzón May 13, 2008Earth Space Science Period 6

refracting effect of the Earth’s atmosphere upon sunlight that in the end reaches the Moon.

The second diagram (bottom) illustrates a partial lunar eclipse, where only half the Moon enters the Earth’s umbra. In such a situation, half the Moon (the one in the penumbra) will be slightly more visible than the other half (the one in the umbra).

10. What is electromagnetic radiation? Electromagnetic radiation is a type of radiation, which is emitted by

celestial objects. It is comprised of electric and magnetic radiation, and includes several different types, such as infrared and ultraviolet radiation, radio waves, microwaves, X rays, and gamma rays.

11. How was the lunar regolith formed?The lunar regolith was a layer of loose, ground-up rock that formed

around 3.8 and 4.6 billion years ago, early in the Moon’s history, during the formation of one of its most prominent features – the highlands. During the first 8000 million years of the Moon’s history, the celestial object was heavily bombarded, and impact craters began to appear as a result. The heavy bombardment caused in the breaking and heating of rocks on the surface of the Moon, which in turn caused the formation of a layer of regolith – a layer of loose, ground-up rock. The regolith formed averages several meters in thickness; although it varies considerably, depending on location.

12. Describe how a lunar month is defined. How long is it? A lunar month is otherwise the term for a complete cycle of the

Moon’s phases, and it takes about 29. 5 days, this is noteworthy as it is longer than the 27.3 days it takes for a lunar revolution.

13. Of all types of electromagnetic radiation, which can the human eye detect?

The humane ye only possess the ability of perceiving visible light.

14. How did the mountain ranges around the maria on the Moon form? Around 3.1 – 3.8 billion years ago in lunar history, during the

formation of its maria, the previous bombardment caused lava to well up to the Moon’s surface from its interior. The lava filled up all the impact basins caused by the impact craters, save for the rims of these basins. These rims later became the mountain ranges characteristic of lunar maria.

15. Why are the temperature fluctuations on the surface of the Moon so extreme compared to those on Earth?

The extreme lunar temperature fluctuations are due to the absence of a lunar atmosphere. In presence of the Sun, the lunar surface may be

Tomás Monzón May 13, 2008Earth Space Science Period 6

heated up to around 400 K, where as it may cool down to -173 K in the Sun’s absence.