Moon - Moon
Moon (1) Add new question
Question
| Option | Answer | Is Correct |
|---|---|---|
| 1 | The Moon is a relatively large, terrestrial, planet-like satellite, with a diameter about one- quarter of the Earths. It is the largest moon in the solar system relative to the size of its planet. The natural satellites orbiting other planets are called ‘moons”, after Earth’s Moon. | |
| 2 | The gravitational attraction between the Earth and Moon cause tides on Earth. The same effect on the Moon has led to its tidal locking: its rotation period is the same as the time it takes to orbit the Earth. As a result, it always presents the same face to the planet. As the Moon orbits Earth, different parts of its face are illuminated by the Sun, leading to the lunar phases: The dark part of the face is separated from the light part by the solar terminator. Because of their tidal interaction, the Moon recedes from Earth at the rate of approximately 38 mm (1.5 in) a year. Over millions of years, these tiny modifications—and the lengthening of Earth’s day by about 23 ps a year—add up to significant changes. During the Devonian period, for example, (approximately 410 million years ago) there were 400 days in a year, with each day lasting 21.8 hours. | |
| 3 | Viewed from Earth, the Moon is just far enough away to have very nearly the same apparent-sized disk as the Sun. The angular size of these two bodies match because, although the Sun’s diameter is about 400 times as large as the Moon’s. it is also 400 times more distant. This allows total and annular eclipses to occur on Earth. The most widely accepted theory of the Moon’s origin, the giant impact theory, states that it formed from the collision of a Mars-size protoplanet called Then with the early Earth. This hypothesis explains the Moon’s relative lack of iron and volatile elements, and the fact that its composition is nearly identical to that of the Earth’s crust. Earth has at least two co-orbital satellites, the asteroids 3753 Cruithne and 2002 AA29. |
Are you prepared and ready for your Exam?
Test your preparation with free online test. Stay ahead from others. Self assessment/analysis at your finger tips.
- Free Registration
- Free 25 test for new members equivalent to 250 question.
- 73225+ free, good quality MCQs included in the system.
Win Prizes
Take part in our quiz competition to win cash prizes, Mobile phone credit and more....
Visit our quiz competition page