Topic 2 - The lunar disc

Question 1

What are Terrae?

Answer 1

Terrae is the collective name for the rocky highlands of the Moon.

Question 2

How were Terrae formed?

Answer 2

Terrae are the lighter parts of the Moon and called the Lunar Highlands.

Question 3

How were the Lunar mountains formed?

Answer 3

Nearer the edges of the Maria, the mountain ranges were thrust upwards, forming mountains.

Question 4

Where is the Sea of Tranquility found on the Lunar disc?

Answer 4

Directly left of the Sea of Crises

Question 5

Where are the Appenine mountains located on the Lunar disc?

Answer 5

The Appenine mountains take the curve of 90° to 180° in a circle moving clockwise. They are located at the top of the Lunar disc next to the Ocean of Storms

Question 6

What follows the First Quarter?

Answer 6

Waxing Gibbous

Question 7

How long is one synodic/solar month?

Answer 7

29.5 days

Question 8

How long is one sidereal month?

Answer 8

27.3 days

Question 9

What is a sidereal month?

Answer 9

The time taken for the Moon to rotate once on its axis

Question 10

What is Synchronous Rotation?

Answer 10

When the Moon rotates on its axis once in the same time it takes to obit Earth once

Question 11

What is a solar month?

Answer 11

The time taken for the Moon to reach the same point in its cycle after one full orbit of the Earth

Question 12

What is one effect of lunar libration?

Answer 12

We can actually observe 59% of the Moon’s surface from Earth

Question 13

How does Diurnal Libration work?

Answer 13

When the Moon rises in the East, more of the Eastern Limb can be seen. When the Moon sets in the West, more of the Western limb can be seen.

Question 14

What is the Moon’s axial tilt?

Answer 14

1.5°

Question 15

By how much is the Moon’s orbit inclined to the ecliptic?

Answer 15

5.1°

Question 16

What is the Ecliptic?

Answer 16

The plane of the Earth’s orbit around the Sun

Question 17

How does Libration in Latitude work?

Answer 17

Because the Moon’s axial tilt is 1.5° and the plane of the Moon’s orbit is inclined to the Ecliptic at 5.1°, the observer can see beyond the Moon’s South and North Poles, depending on where the observer is located.

Question 18

How does Libration in Longitude work?

Answer 18

Because the Moon’s orbit is elliptical, there are points at which the Moon is travelling faster. Therefore at one point, the Moon might have rotated 1/4 but it has moved more than 1/4 around its orbit. Therefore from Perigee to Apogee, more of the Western limb can be seen.