the Moon

Astronomical unit

An astronomical unit (AU) is the average distance between the sun and the earth. It is about 150 million kilometres. The distance between Mercury and the sun is around 1/3 AU, while the distance between the sun and pluto is 40 AU.

Tides

Lunar tides

Lunar tides occur due to the moon's gravity pulling on the earth's water. It causes bulges on the water surface. High tide occurs when one is in the bulges.

Spring and neap tides

Neap tides occur when the sun and moon are at opposite sides of the earth, while neap tides occur when the angle between the sun, earth and moon is 90°.

Lunar recession

The moon is receding from the earth due to the earth's tides. Due to the earth's rotation, the tidal buldge sits slightly ahead of the moon. This results in some of the earth's rotational energy being transferred to the moon

Lunar libration

Libration is the perceived wagging and waning of the moon as it orbits around the earth. It is due to the eccentricity of the moon's orbit, resulting in it appearing to lag in its orbit. It is also due to the slight inclination of the moon's axis of rotation and the plane of its orbit around the earth.

It is also due to diurnal libration, courtesy to the earth's rotation, which carries the observer from seeing one side of the moon's surface to another as the observer is not in the centre of the earth.

Atmospheric structure

The moon has a very thin layer of gases on it (i.e. its exosphere). Said gases are easily lost to space and it is so thin that atoms rarely collide.

Composition

The moon's atmosphere contains 3 primary gases - neon, helium and hydrogen. Methane, carbon dioxide, ammonia and water are also present in small amounts.

Terrestrial features

Mars has a metal-rich core and a rocky mantle, while Venus has a core of metal, a mantle of dense rock and a crust of rock. Most terrestrial planets have topological features.

Lunar features

The moon's surface contains crates, maria, valleys and mountains.

The moon's craters are caused by asteroids and meteorites colliding with the lunar surface, while lunar maria are caused by ancient volcanic eruptions on the moon.

The moon is basically a desert with plains, mountains and valleys.

Reflection

Perhaps the session could've been slower. Not enough time was given to type in the information on the blog, and I had not mastered the skill of fast typing.

Perhaps the session could've been slower. Not enough time was given to type in the information on the blog, and I had not mastered the skill of fast typing.