Topic 2 - The lunar disc Flashcards
What are Terrae?
Terrae is the collective name for the rocky highlands of the Moon.
How were Terrae formed?
Terrae are the lighter parts of the Moon and called the Lunar Highlands.
How were the Lunar mountains formed?
Nearer the edges of the Maria, the mountain ranges were thrust upwards, forming mountains.
Where is the Sea of Tranquility found on the Lunar disc?
Directly left of the Sea of Crises
Where are the Appenine mountains located on the Lunar disc?
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
What follows the First Quarter?
Waxing Gibbous
How long is one synodic/solar month?
29.5 days
How long is one sidereal month?
27.3 days
What is a sidereal month?
The time taken for the Moon to rotate once on its axis
What is Synchronous Rotation?
When the Moon rotates on its axis once in the same time it takes to obit Earth once
What is a solar month?
The time taken for the Moon to reach the same point in its cycle after one full orbit of the Earth
What is one effect of lunar libration?
We can actually observe 59% of the Moon’s surface from Earth
How does Diurnal Libration work?
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.
What is the Moon’s axial tilt?
1.5°
By how much is the Moon’s orbit inclined to the ecliptic?
5.1°
What is the Ecliptic?
The plane of the Earth’s orbit around the Sun
How does Libration in Latitude work?
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.
How does Libration in Longitude work?
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.
