topic 2 Flashcards
what seas/maria
Seas/Maria – large dark grey and smooth these are made of volcanic basalt rock
what are highlands/tarrae?
Highlands/Terrae - lighter grey, mountainous and highly cratered are made of igneous rock called anorthosite
what is ejecta?
Ejecta – “Rebound” splattered material caused by meteoroid impacts
What are rays?
Rays - bright streaks of ejecta
what is Diurnal motion?
Diurnal motion is the daily motion of stars and other celestial bodies across the sky
what is the near side?
This is the side we can see from Earth. It is familiar as this side always faces towards Earth.
what is the far side?
This is the side we cannot see from Earth. It is alien to us as this side always faces away from Earth.
what does it mean by the moon is tidally locked?
We say that the Moon is tidally locked – the period of rotation is equal to the orbital period.
why can the moons rotation be origionally faster?
Originally the Moon’s rotation would have been faster but it has been slowed by internal tidal gravitational forces.
what is a sideral month and how long is it?
A sidereal month is the time it takes for the Moon to complete a full orbit around the Earth
27.3 days
what is a synodic month
A synodic month is the time it takes for the phases of the moon to complete a full cycle
A synodic month is 29.5 days
how much of the earth can we see?
59%
what is lunar libration?
lunar libration - the wobbling of the Moon caused by changes in their perspective of Earth-bound observers.
It permits an observer to see slightly different hemispheres of the surface at different times.
what also permits you to see more of the moon?
Also being at high or low latitudes will allow you to see under and over the polar regions (slightly).
what is the moons equator inclined by
The Moon’s equator is inclined (tilted) to the plain of it’s orbit around Earth by 1.5o
