EARTH and the MOON
The third rock from the Sun. Earth is our home planet. It is the only planet in the solar system that has liquid water and the only planet (we know so far) that has intelligent(?) life.
The structure of Earth is made up of layers. The inner core is made up of iron and nickel. The very center is probably solid, but the outer part of the core is probably a dense liquid. The next layer out is called the mantle. The mantle is the largest, or thickest area of the planet. The final layer is the crust. The Earth's atmosphere is also layered. There are 5 layers: Ionosphere (90 KM up and 350 KM thick), Mesosphere (50 KM up and 40 KM thick), Stratosphere (18 KM up and 30 KM thick), Tropopause (14 KM up and 4 KM thick), and, Troposphere (Ground level to 14 KM up).
Information regarding the Earth falls more into the category of geology so I will leave the rest of the explanations up to the geologists.
The MOON is the Earth's satellite. It revolves around the Earth once every 27 days, 7 hours and 43 minutes. The Moon's diameter is 3476 KM (2159 miles). The Moon is EASILY viewed, studied, drawn, and photographed. You don't even need binoculars or a telescope to start, just your eyes! The Moon has one side that always faces the Earth. The other side, or dark side as some call it, is NOT always dark! When the Moon is between the Sun and the Earth, the back side of the Moon is facing directly towards the Sun.
For some reason, the back side of the Moon is by no means as interesting as the side that faces us. The craters on the back side are much smaller and less spectacular. Let's break the side that faces us into 2 sections:
Tips for Lunar Observing
The terminator is the line where the light stops and the shadows of the lunar darkness begin. Along this line is where you can see the most amount of detail in the edge of the craters, the mountains, and the rilles. Aim your scope or binoculars to the top of the Moon and work your way down the terminator. Do this each night and you will see more and more and more every night. Keep notes if you wish, about the different features you notice. You may even want to draw the features as you see them.
DON'T try and view the Moon when it is full. This is when the least number of features are clearly visible and the light from the full Moon coming through your binoculars or an unfiltered telescope can actually make you eyes ache! The Moon only reflects about 5% of the light it receives, but the light from the Moon can easily cast a shadow!
After the Moon has past the "full" phase, the light will begin to recede leaving more details to see from a different angle. This time, the light will be coming from the east side of the Moon, causing the shadows to be cast in the opposite direction than when the Moon was going from "new" to "full". You will see the same features, just with a different perspective. This time, viewing the Moon will be a little more difficult. See, the Moon at last quarter won't rise until midnight and the crescent Moon won't rise until nearly 3:00am! This makes it more of a challenge (yeah right!)