Don't forget about our Celestial Hokey Pokey!

The earth is tilted on it's axis (the red line) at an angle of 23.5 degrees. That means what we think of as straight up and done is not straight up and down for the rest of the solar system. We "walk" crooked like the leaning Tower of Pisa. While everything else including the people is straight up... the tower leans. The same is true of our solar system. While most things stand up straight as they rotate around the sun.... we rotate around without standing up straight. Like the tower we lean at an angle. 23.5 degrees

While Zenith is like a "true north" for the Sun, it's not the same as our north because... we lean. Our north instead is called the Celestial North Pole.

The same is for Nadir and Celestial South Pole. Nadir is the "true south" of the Sun. But because we lean our south isn't exactly lined up. So, ours is called the Celestial South Pole.

Now the Ecliptic and Horizon go together. The ecliptic is the line that cuts right across the stomach of the Sun. That line stretches out across the solar system. When it cuts across the stomach of the Earth we call it the horizon. But this is the angle from the Sun. Again, because we are tilted we like to think that when you cut a line across the Earth's stomach you get the Celestial Equator. The Ecliptic and Celestial Equator do not overlap because we are.... tilted!

Now, if you were to cut a line down the Earth from head to toe, right down its axis, this line would be called the Celestial Meridian.

Next up

Previous

Parts+Of+A+Galaxy+Part+1